Opposing groups of campaigners gathered outside the UK Supreme Court in London on Monday as judges started hearing the government's appeal against a ruling that Parliament must hold a vote before Britain's European Union exit negotiations can begin.

Prime Minister Theresa May plans to trigger two years of divorce talks before the end of March by invoking Article 50 of the EU's key treaty, using centuries-old government powers known as royal prerogative.

Those powers - traditionally held by the monarch but now used by politicians - allow the government to join or leave international treaties without consulting lawmakers.

Financial entrepreneur Gina Miller and hairdresser Deir Dos Santos went to court to argue that leaving the EU will remove some of their rights, including free movement within the 28-nation bloc, and that shouldn't be done without Parliament's approval.

Last month, three High Court judges agreed - but the government says they have misinterpreted the law.

The case has raised a constitutional quandary and inflamed the country's heated debate about Brexit.

November's ruling infuriated pro-Brexit campaigners, who saw the lawsuit as an attempt to block or delay Britain's EU exit.

Miller says she has received abuse and death threats.

She arrived at court Monday with her lawyers, greeted by cheers from pro-EU campaigners dressed as judges atop an open-topped double-decker bus.

A banner on the side read "In democracy, Leave hypocrisy."

"Nigel, where are you?" they sang mockingly, in reference to former UK Independence Party leader Nigel Farage, a prominent voice in the leave campaign.

He had promised to lead a march on the Supreme Court to demand judges respect the will of the majority.

It was cancelled last week after organisers said there was a risk it could be hijacked by far-right extremists.

Two anti-EU protesters held placards, one calling the case an "establishment stitch-up."

Many legal experts say the government will likely lose its appeal and be forced to give Parliament a vote.

London - 5 December 2016

1. Exterior of UK Supreme Court

2. Close up of European Union flag

3. Police entering Supreme Court

4. Wide of pro-Remain protesters from Britain for Europe singing as they arrive in open-topped London bus UPSOUND (English) "Nigel, where are you?"

5. Various of protesters outside court building, holding EU and UK flags

6. SOUNDBITE (English) David Gullant, Protester from Surrey branch of Britain for Europe:

"I am a British citizen, but I want to make sure that the UK due process is followed. So this is not about Brexit pros and cons, it's about making sure that if you have an Act of Parliament, only Parliament can change that Act of Parliament. It is not up to the prime minister to overturn it, it has got to go through due process."

7. Pro-Brexit protester Julia Waller

8. SOUNDBITE (English) Julia Waller, pro Brexit protester

"Well, I hope that the government, I hope Theresa May's hand, is strengthened. We've got to give her some credit - she can't expose her hand to Europe. Europe doesn't have our best interests at heart anyway, and I think we want to be free, and when people voted they didn't just vote for a soft Brexit or a grey Brexit, those words didn't exist then. We just voted for Brexit. We want to get out - end of (discussion)."

9. Pan from pro-Europe protesters to Supreme Court

As UK's Prime Minister Theresa May wants to start Britain's divorce from the European Union (EU), eleven judges may stand in her way.

On Monday, May's government will ask the justices of the Supreme Court to overturn a ruling that Parliament must hold a vote before Britain's exit negotiations can begin, a case that has raised a constitutional quandary and inflamed the country's heated debate about Brexit.

May plans to trigger two years of divorce talks before the end of March 2017 by invoking Article 50 of the EU's key treaty, using centuries-old government powers known as royal prerogative.

The powers - traditionally held by the monarch but now used by politicians - enable decisions about joining or leaving international treaties to be made without a vote of Parliament.

A hairdresser and a financial entrepreneur, Deir Dos Santos and Gina Miller, went to court to argue that leaving the EU will remove some of their rights, including free movement within the bloc, and that shouldn't be done without Parliament's approval.

Last month, three High Court judges agreed, but the government says they have misinterpreted the law.

Government lawyers led by Attorney General Jeremy Wright will argue this week that the British people have spoken by voting in a June 23 referendum to leave the EU.

In written arguments published before Monday's hearing, government lawyers say the use of royal prerogative to start the talks is "constitutionally appropriate and lawful."

Many legal experts say the government will likely lose its appeal and be forced to give Parliament a vote, but the government was left with little choice than to proceed with the case anyway.

"It's politically problematic, I think, to be seen to not pursue all legal avenues to obstruct this attempt to, in the eyes of some critics, derail the Brexit process," says Jeff King, Professor of Law, University College London.

In a reflection of the constitutional importance of the case - which hinges on the balance of power between Parliament and the executive - all 11 Supreme Court judges will hear the appeal, the first time the full court has sat since it was founded in 2009.

The case is scheduled to last four days, with a ruling likely in January.

Complicating the picture are new participants including the Scottish government, which argues the Edinburgh-based Scottish Parliament should get a vote, too.

Britons voted by 52 to 48 percent on June 23 to leave the EU, but voters in Scotland strongly backed staying in, and the Scottish government says they should not be dragged out of the EU against their will.

London - 1 December 2016

1. Exterior of UK Supreme Court building, traffic on street

2. Close of symbol reading (English): "The Supreme Court"

3. Various exteriors of Supreme Court building

4. Various of Jeff King, Professor of Law, University College London, looking at book

5. SOUNDBITE (English) Jeff King, Professor of Law, University College London:

"Well, I think that there are two reasons probably (why the government appealed the High Court ruling that Parliament must hold a vote before negotiations of Britain's exit from the European Union can begin). The first is that it was very confident that it would win at the beginning, and I think it's reluctant to move from that position of confidence. And secondly, it's politically problematic, I think, to be seen to not pursue all legal avenues to obstruct this attempt to, in the eyes of some critics, derail the Brexit process."

6. Cutaway of King

7. SOUNDBITE (English) Jeff King, Professor of Law, University College London:

"The reaction in some of the media (to the government's loss in the High Court), in particular in the Daily Mail and the Daily Express was, I would say, outrageous. It has been common to criticise judges in the past and I think criticism of judges is perfectly acceptable - they are public officials after all, but this type of language, 'Enemies of the people' (Daily Mail headline the day after the ruling) reminded me of the kinds of things we saw in Nazi Germany."

8. Cutaway of King

9. SOUNDBITE (English) Jeff King, Professor of Law, University College London:

"This is quintessentially a role for judges to play. It's an unclear legal position. The devolved governments don't agree, many members of parliament don't agree. There needs to be an authoritative ruling on what the role of these statutes is in the Brexit process, and that can only be given by a court."

10. Cutaway of King

11. SOUNDBITE (English) Jeff King, Professor of Law, University College London:

"I think that a government loss at the Supreme Court would not derail the Brexit process, but I also think it would be more than a mere speed bump because having to bring forward legislation to give notice would mean that there would be a participation of a much broader range of voices, both in Parliament and in the devolved legislatures and among the devolved governments. And when these voices are heard there is a political obligation of sorts to respond to these voices, to take them into account, to not proceed in a way that ignores them altogether, and I think that will make a difference to the outcome of the Brexit process, but I don't think it will stop it."

12. Cutaway of King

13. Pan of books

14. Various exteriors of Houses of Parliament

Small groups of protesters held rival demonstrations on Monday as judges inside the Supreme Court in London were hearing arguments as to whether the government had the right to leave Europe without parliamentary approval.

Britain's Supreme Court began hearing a landmark case on Monday that will decide who has the power to trigger the UK's exit from the European Union - the government or Parliament.

The legal battle has major constitutional implications for the balance of power between the legislature and the executive, and has inflamed Britain's already raw wound over how and whether to leave the EU.

Prime Minister Theresa May plans to trigger Article 50 of the EU's key treaty by the end of March, using centuries-old government powers known as royal prerogative.

The powers - traditionally held by the monarch but now used by politicians - enable decisions about joining or leaving international treaties to be made without a parliamentary vote.

London - 5 December 2016

1. Pro-Europe demonstration in front of Supreme Court

2. Tilt down of sign reading (English): "Stop Brexit fight racism and the scapegoating of immigrants. Defend freedom of movement."

3. Various of pro-Europe protesters chanting, holding banners

4. Pan from police to protesters in front of Supreme Court

5. Rival protest groups in front of Supreme Court, police officers at scene

6. Pro-Europe protesters shouting (English): "Brexit is racist, stop Brexit now!"

7. Smart phone screen showing protesters

8. Rival protesters discussing

9. Pro-Brexit protesters, woman waving Union flag

10. Man being led away by police

11. Policewoman

12. Supreme Court and protesters

Britain's government must get parliamentary approval before starting the process of leaving the European Union, the Supreme Court ruled on Tuesday, potentially delaying Prime Minister Theresa May's plans to trigger exit negotiations by the end of March.

The 8-3 ruling from the judges forces the government to put a bill before Parliament, giving pro-EU politicians a chance to soften the terms of Brexit - Britain's exit from the EU.

"Leave" campaigners had objected, saying Parliament shouldn't have the power to overrule the electorate, which voted to leave the bloc in a June 23 referendum.

The Supreme Court's decision doesn't mean that Britain will remain in the EU - but it could delay the process.

Still, May's Brexit secretary, David Davis, told the House of Commons on Tuesday that the government timetable remained on track, and that officials would introduce a bill within days.

"They (parliament) need to be involved before we leave," said Charlie Mullins, founder of Pimlico Plumbers, who helped fund Article 50 legal challenge.

May had argued the referendum gave her a mandate to take Britain out of the EU and that discussing the details of her strategy with Parliament would weaken the government's negotiating position.

UKIP leader Paul Nuttall said the result was what he expected, saying "I think we've lost the battle today and I'm disappointed but not surprised, but we will win the war."

London - 24 January 2017

1. Pan down UK Supreme Court entrance

2. Police outside

3. Top shot media and entrance

4. Set up of Charlie Mullins, founder of Pimlico Plumbers

5. Close up Mullins' tie

6. SOUNDBITE (English) Charlie Mullins, founder of Pimlico Plumbers, helped fund Article 50 legal challenge:

"Well I think it was all unnecessary. If she would have got parliament involved, rather than you know, saying that she's gonna get on with it, then she was saying, 'oh, they can vote on this once she's negotiated a deal' - well that's all too late then. Once she's negotiated a deal, once we've left the EU and we're offered the deal we've got, there is no point in parliament getting involved. They need to be involved before we leave. And now I think they can put enough pressure on to her to make sure we get a soft Brexit."

7. Pan down Supreme Court

8. Various pro-EU demonstrators

9. Various exteriors of UK parliament

10. Various cutaways of Paul Nuttall, UK Independence Party leader

11. SOUNDBITE (English) Paul Nuttall, UKIP leader:

"I think it's what we expected, I think we've lost the battle today and I'm disappointed but not surprised, but we will win the war. And now these guys behind me in the House of Commons and the House of Lords have a duty to enact the will of the people and I want to make it clear what that will is. People voted on mass on June 23rd to leave the European Union. They also voted the leave the single market. The Prime Minister of the day, David Cameron, the Chancellor, the Foreign Secretary of the day, Philip Hammond, they all made it clear, leaving the EU means leaving the single market. The British people went out and did that by a score of 52 percent. So leaving must mean leaving."

12. Mid of Parliament

13. Various set ups Andrew Blick, Director History and Policy organisation and Lecturer King's College London

14. SOUNDBITE (English) Andrew Blick, Director History and Policy and Lecturer King's College London:

"The courts upholding that principal is a very important constitutional moment that no doubt will appear in all the textbooks for years to come. No question about the constitutional significance. The political significance is a bit more complicated. What political difference will it really make? It seems unlikely that the Commons, the House of Commons, the elected chamber of parliament, would want to be seen to be blocking Brexit, to be seen to be resisting the will of the people as expressed in a referendum. That seems very unlikely. There is perhaps an outside chance that the House of Lords, the unelected chamber, might offer some kind of resistance to the bill."

15. Cutaway

16. SOUNDBITE (English) Andrew Blick, Director History and Policy and Lecturer King's College London:

"I think that timetable (set out by British Prime Minister Theresa May) still looks very plausible, but the consequence of this judgment today is that the matter is slightly out of her (May) hands in that now she has to get statutory authorisation, she has to take a bill through parliament, she has to follow through those parliamentary procedures. It can be done quickly but it does require both Houses of Parliament to agree to it if she wants it happen quickly, so there is a slight variable in there, that wasn't in there before."

17. Various exteriors of Parliament

A law professor said an appeal of the High Court ruling stating that the British prime minister can't trigger the UK's exit from the European Union without parliamentary approval was unlikely to succeed.

Jeff King, of University College London, said Thursday's comprehensive ruling on an expansive set of grounds could cause the government's argument to fail.

But King cautioned that those hoping for a reversal of the referendum result would likely be disappointed.

London - 3 November 2016

1. Various set up shots of Professor of Law Jeff King, University College London

2. SOUNDBITE (English) Jeff King, Professor of Law, University College London:

"It was very clear, there are many points that rather than just the courts saying that we don't need to rule on this point, the court rather said that we think that point is completely untenable, in some cases suggesting that an argument was divorced from reality. So a court that was very divided on this question might well have given a much slimmer narrower ruling based on very few grounds instead of an expansive set of grounds, dealing with only a few crucial points instead of dealing with many more subtle points, but it chose the latter route. In so it gave a comprehensive ruling on many points, many of which could cause the government's argument to fail. And that gives me confidence that an appeal would be unlikely to succeed under the circumstances."

3. Cutaway of King

4. SOUNDBITE (English) Jeff King, Professor of Law, University College London:

"It may feel that legally there are arguments that it wishes either to make again or to bring new arguments to the attention of the Supreme Court. It may feel that the political consequences of not pursuing the appeal could be problematic, it might be accused of not having followed up every available avenue. These type of accusations are already being made about the pleadings of the government in this very case. So for those reasons, it may have good political and legal reasons to appeal. My sense is that the appeal would be unlikely to be successful. I think that Supreme Court would have even more confidence to be as unequivocal as this court has been."

5. Various of King

6. SOUNDBITE (English) Jeff King, Professor of Law, University College London:

"If that 48 percent (those supporting remain) is hoping this legal challenge will stop Brexit, I think they will be disappointed. I think whether Brexit goes ahead will be a function of where Parliament takes this issue from here. And that's exactly what all the judges in the case were taking pains to point out.''

7. Cutaway of King

Britain's government must get parliamentary approval before starting the process of leaving the European Union, the Supreme Court ruled on Tuesday.

The decision potentially delays Prime Minister Theresa May's plans to trigger exit negotiations by the end of March.

London - 24 January 2017

1. Various of Parliament

2. Evening Standard newspaper vendor talking to security officer

3. Close of Evening Standard newspaper, reading (English) "Judges' blow to May over Brexit."

4. Vendor and security officer talking

5. Close of newspaper lead, reading (English) "PM can't trigger Article 50 without Parliament backing, says supreme court in historic ruling."

The four day hearing about who has the power to trigger the EU exit - lawmakers or the government- wrapped up in London on Thursday.

The Supreme Court has been asked to rule on a major constitutional issue: Does the power to take Britain out of the EU rest with the executive - May's government - or with Parliament?

The government argued it can use powers known as royal prerogative to invoke Article 50 of the EU's key treaty, the formal trigger for exit talks from the 28-nation bloc.

Speaking after the conclusion of the proceedings Attorney General, Jeremy Wright QC, said there has been a "clear expectation that the outcome of the referendum would be honoured - inside and outside Parliament, before, during and after the referendum campaign".

Lawyers challenging the government say leaving the EU will change Britain's laws and remove citizens' rights, including free movement within the bloc - and that can't be done without legislation in Parliament.

Gina Miller, the lead claimant, said the process has been "emotionally and physically, mentally quite draining" but as the days have gone on she has realised the enormity of the case.

The immediate future of the Brexit process now rests in the hands of the 11 Supreme Court justices, with a decision expected in January.

UK POOL

London - 8 December 2016

++NIGHT SHOTS++

1. Lawyers bowing as judges exit at the end of the hearing

2. Various of people leaving court

3. SOUNDBITE (English) Jeremy Wright QC, UK Attorney General:

"There has been a clear expectation that the outcome of the referendum would be honoured - that's inside and outside Parliament, it's before, during and after the referendum campaign. Members of Parliament voted overwhelmingly to have this referendum and as you know, as recently as yesterday evening, Parliament's been continuing to have a say about this."

++BLACK FRAMES++

4. SOUNDBITE (English) Jeremy Wright QC, UK Attorney General:

"Look, we don't decide which cases are brought. The claimants bring their case, as they did. When we believe, as we did, that judges weren't right in the judgement they reached in the divisional court then the right thing is to appeal that judgement. That's what we've done and we now wait and see what the Supreme Court has to say on the matter."

5. Various of Gina Miller, the lead claimant, leaving court

6. SOUNDBITE (English) Gina Miller, lead claimant:

"It's been, the bank of cameras and coming in, the whole thing has been quite emotionally and physically, mentally quite draining. I almost feel as though I'm back into first year law college listening to lectures but one after the other after the other. And then there is the enormity of the fact that I'm sitting in the Supreme Court hearing my name being mentioned and referred to as the Miller case, it's all quite unusual to take it, you know it's just not normal sort of every day. But what's also important as the days have gone on, is to realise the enormity of the case."

++ENDS ON SOUNDBITE++

Britain's Supreme Court will rule on Tuesday on whether the prime minister or Parliament has the right to trigger the process of taking Britain out of the European Union.

The 11 justices will either uphold an earlier ruling giving Parliament a direct role in invoking Article 50 of the EU's Lisbon Treaty or reject that ruling in favour of the government's claim it can do so without a vote in Parliament.

Article 50, which has never been used before, starts the formal process of taking Britain out of the 28-nation EU.

The legal battle follows a successful High Court action led by businesswoman Gina Miller.

A reversal of the lower court ruling would give Prime Minister Theresa May the authority to start Article 50 negotiations when she chooses without input from Parliament.

She has said, however, that Parliament will be asked to approve any Brexit deal reached at the conclusion of the talks.

UK POOL

London - 24 January 2017

1. Lord Richard Keen QC, Advocate General for Scotland, (wearing red scarf) and Jeremy Wright UK Attorney General arriving at Supreme Court

2. Various of lead claimant Gina Miller arriving, posing for cameras

3. Various of more arrivals

4. Protester with banner being led away by police

5. Police arriving

Austrian Presidential candidate Norbert Hofer said that if the European Union is not reformed to become less centralised, it would be right to ask Austrians if they want to remain part of the bloc.

The right-wing candidate said Austria joined the EU "under different circumstances" and if the bloc moves towards further integration "then you would have to ask again: do you want to be a member in a centralist Europe? The result could absolutely be 'yes'. But you have to ask the question."

Hofer said he hopes that the current EU crisis after the Brexit vote could have a "healing effect" which could even invigorate the Union.

Hofer added that he was against Turkey joining the EU but in favour of tight economic and friendly relations with the country saying, "for me Turkey is not a European country with the exception of a few square kilometres."

He also criticised EU Commission President Jean-Claude Juncker, saying he didn't represent "the picture of the European Union we wish".

Hofer will head his right-wing Freedom Party in a rerun of the presidential election ordered by the country's highest court on grounds of wide-spread voting irregularities in the first ballot.

Austria's chancellor on Tuesday said the government has set October 2 as the date for the rerun of the presidential election

The date, announced Tuesday by Chancellor Christian Kern, still has to be approved by parliament, but that is only a formality.

The Constitutional Court on Thursday had announced that the May runoff between Hofer and left-leaning independent Alexander Van Der Bellen must be repeated.

Van der Bellen had won by less than 30,000 votes.

The ruling essentially matched a challenge by Hofer's party, which asserted the election's results were distorted by mistakes and sloppiness in counting absentee ballots and by other ballot violations.

Austrian Presidential candidate Norbert Hofer said that if the European Union is not reformed to become less centralised, it would be right to ask Austrians if they want to remain part of the bloc.

The right-wing candidate said Austria joined the EU "under different circumstances" and if the bloc moves towards further integration "then you would have to ask again: do you want to be a member in a centralist Europe? The result could absolutely be 'yes'. But you have to ask the question."

Hofer said he hopes that the current EU crisis after the Brexit vote could have a "healing effect" which could even invigorate the Union.

Hofer added that he was against Turkey joining the EU but in favour of tight economic and friendly relations with the country saying, "for me Turkey is not a European country with the exception of a few square kilometres."

He also criticised EU Commission President Jean-Claude Juncker, saying he didn't represent "the picture of the European Union we wish".

Hofer will head his right-wing Freedom Party in a rerun of the presidential election ordered by the country's highest court on grounds of wide-spread voting irregularities in the first ballot.

Austria's chancellor on Tuesday said the government has set October 2 as the date for the rerun of the presidential election

The date, announced Tuesday by Chancellor Christian Kern, still has to be approved by parliament, but that is only a formality.

The Constitutional Court on Thursday had announced that the May runoff between Hofer and left-leaning independent Alexander Van Der Bellen must be repeated.

Van der Bellen had won by less than 30,000 votes.

The ruling essentially matched a challenge by Hofer's party, which asserted the election's results were distorted by mistakes and sloppiness in counting absentee ballots and by other ballot violations.

Vienna - 5 July 2016

1. Austrian presidential candidate Norbert Hofer at desk

2. Hofer at desk

3. Hands shuffling through documents

4. SOUNDBITE (German) Norbert Hofer, Austrian presidential candidate:

"My opinion is that should treaties be developed that say 'we disempower the member states, we build a centralist Europe under complete elimination of the unanimity principle' then you would have to ask the Austrians if they wanted to be a member in such a Europe. Because the joining of the European Union happened under different conditions. That was a very important promise that we as a small country, also because of the unanimity principle, can have a say in important questions. Then this would be a different Europe. Then you would have to ask again: do you want to be a member in a centralist Europe? The result could absolutely be 'yes'. But you have to ask the question."

5. Hofer during interview

6. Various of portrait of Tyrolean leader Andreas Hofer on wall

7. SOUNDBITE (German) Norbert Hofer, Austrian presidential candidate:

"What happens if Turkey becomes a member of the European Union? That would also be a completely different Europe. And I think the European Union could hardly cope with this. I'm in favour of a privileged partnership with Turkey, with tight economic relations, friendly relations. But for me Turkey is not a European country with the exception of a few square kilometres."

8. Hofer during interview

9. Hofer's hands

10. SOUNDBITE (German) Norbert Hofer, Austrian presidential candidate:

"I strongly believe that the people in responsible positions in the European Union and and the member states have learned from this and also realise how critical such a decision can be. I believe in a healing effect. And maybe the European Union can even come out invigorated out of this crisis - if you make the right decisions and if the right personalities are in power."

11. Hofer during interview

12. SOUNDBITE (German) Norbert Hofer, Austrian presidential candidate:

"For me Juncker is not someone who should have this position now in such a critical situation. My view is similar to, I think Merkel, who seems to have already made some remarks. For many citizens Juncker doesn't represent the picture of the European Union we wish. This non-serious appearance, slapping heads of states and governments when they arrive. He must be aware of the big responsibility he is bearing in this position. You can't play the comic relief, that's just not possible."

13. Various of Hofer at his desk

UK Supreme Court judges were heading in for a third day of a four-day hearing as they considered whether government or Parliament has the power to lead the country out of the European Union.

Prime Minister Theresa May plans to launch EU exit talks by the end of March using ancient powers known as royal prerogative, which enable decisions about joining or leaving international treaties to be made without a parliamentary vote.

Several claimants went to court to argue that leaving the EU would remove some of their rights, including free movement within the bloc, and that such an action could not be taken without legislation in Parliament.

Last month the High Court agreed that the government cannot trigger Article 50 of the EU's key treaty, launching two years of exit negotiations, without lawmakers' support.

The government is challenging that decision at the country's top court - leaving the 11 justices to rule on the balance of power between the legislature and the executive.

CORRECTION - CLIENTS PLEASE NOTE THE MAN IN SHOT 1 IS ACTUALLY CLAIMANT CHARLIE MULLINS OF PIMLICO PLUMBERS, NOT HAIRDRESSER DEIR DOS SANTOS AS ORIGINALLY STATED

POOL - AP CLIENTS ONLY

London - 7 December 2016

1. Various of entrepreneur Charlie Mullins of Pimlico Plumbers arriving at Supreme Court. Mullins, the boss of London-based Pimlico Plumbers is one of a group of business people helping to fund the court challenge

UK Supreme Court judges were heading in for a third day of a four-day hearing as they considered whether government or Parliament has the power to lead the country out of the European Union.

Prime Minister Theresa May plans to launch EU exit talks by the end of March using ancient powers known as royal prerogative, which enable decisions about joining or leaving international treaties to be made without a parliamentary vote.

Several claimants went to court to argue that leaving the EU would remove some of their rights, including free movement within the bloc, and that such an action could not be taken without legislation in Parliament.

Last month the High Court agreed that the government cannot trigger Article 50 of the EU's key treaty, launching two years of exit negotiations, without lawmakers' support.

The government is challenging that decision at the country's top court - leaving the 11 justices to rule on the balance of power between the legislature and the executive.

POOL

London - 7 December 2016

1. Lead claimant Gina Miller and team arriving at Supreme Court

2. Lord Richard Keen QC, Advocate General for Scotland, and Jeremy Wright UK Attorney General arriving

Proceedings began on Monday at the UK's highest court as the British government attempts to overturn a ruling that Parliament must hold a vote before Britain's European Union exit negotiations can begin.

Prime Minister Theresa May plans to trigger two years of divorce talks before the end of March by invoking Article 50 of the EU's key treaty, using centuries-old government powers known as royal prerogative.

The powers - traditionally held by the monarch but now used by politicians - enable decisions about joining or leaving international treaties to be made without a parliamentary vote.

Financial entrepreneur Gina Miller and hairdresser Deir Dos Santos went to court to argue that leaving the EU will remove some of their rights, including free movement within the bloc, and that shouldn't be done without Parliament's approval.

Last month, three High Court judges agreed.

But the government says they have misinterpreted the law.

Government lawyers led by Attorney General Jeremy Wright will argue this week that the British people have spoken by voting in a June 23 referendum to leave the EU.

They say a parliamentary vote would mean getting lawmakers "to answer precisely the same question which was put by Parliament to the electorate and has been answered in the referendum."

Many legal experts say the government will likely lose its appeal and be forced to give Parliament a vote.

In a reflection of the constitutional importance of the case - which hinges on the balance of power between Parliament and the executive - all 11 Supreme Court judges will hear the appeal, the first time the full court has sat since it was founded in 2009.

The case is scheduled to last four days, with a ruling likely in January.

UK POOL

London - 5 December 2016

1. Zoom in from man waving European Union flag outside court building to flag

2. Attorney General for England and Wales Jeremy Wright arriving with his associates

3. Protest bus passing outside court, people on it chanting UPSOUND (English) "Nigel, where are you!"

4. Gina Miller, investment fund manager and philanthropist who was one of the team that won the High Court ruling, arriving with her associates, posing for photographers in front of court entrance

FOR CLEAN VERSION SEE STORY NUMBER: 4231491, 4231476, 4231482

British Prime Minister Boris Johnson says he strongly disagrees with the Supreme Court ruling that Parliament's suspension was illegal.

He says the government will respect the decision but indicated he could try to suspend it again.

Johnson said in New York Tuesday that "I strongly disagree with this decision of the Supreme Court" and "I don't think this was the right decision."

He added: "It's perfectly usual to have a Queen's Speech, that's what we want to do."

The Queen's Speech outlines the government's plan for the coming session of Parliament.

Johnson's office meanwhile said he will not resign.

Downing St. said Johnson will fly back from a U.N. General Assembly in New York overnight, earlier than planned.

That will bring him back to London by the time Parliament resumes on Wednesday.

This comes as UK House of Commons Speaker John Bercow welcomed the Supreme Court's ruling that the suspension of Parliament was illegal and said that members are set to resume their work on Wednesday morning.

He said citizens are "entitled" to have Parliament perform its core constitutional duties.

Whitle an anti-government protester outside the court welcomed the ruling and said MP's should go back to Parliament as soon as possible.

"We are in a national crisis right now, and we leave the European Union in just over a month so we need to get back in there and start talking about it because if we don't then we're gonna have some big problems," said Jacob Archbold.

Pro-Brexit demonstrators, meanwhile, chanted slogans of support for Johnson.

But Brexit supporter Michael McFadden also said that Johnson and the Conservatives had "destroyed themselves" and accused former Prime Minister Theresa May of making Brexit backers "look a bunch of fools and we are not a bunch of fools."

The landmark decision immediately prompted calls for Johnson to quit.

ASSOCIATED PRESS

New York - 24 September 2019

1. SOUNDBITE (English) Boris Johnson, British Prime Minister:

"I strongly disagree with this decision of the Supreme Court. I have the utmost respect for our judiciary. I don't think this was the right decision. I think that the prerogative of prorogation has been used for centuries without this kind of challenge. It's perfectly usual to have a Queen's Speech, that's what we want to do. But more importantly let's be in no doubt, there are a lot of people who want to frustrate Brexit. There are a lot of people who basically want to stop this country coming out of the EU."

++SEPARATED BY WHITE FLASH++

2. SOUNDBITE (English) Boris Johnson, British Prime Minister:

"As the law stands we leave on October the 31st and I'm very hopeful that we will get a deal and I think what the people of the country want is to see our parliamentarians coming together, working on, in the national interest to get this thing done and that's what we're going to do."

++SEPARATED BY WHITE FLASH++

UK POOL

London – 24 September 2019

3. SOUNDBITE (English) John Bercow, Speaker of the House of Commons of the United Kingdom:

"In the light of that explicit judgment I have instructed the House authorities to prepare, not for the recall - the prorogation was unlawful and is void - to prepare for the resumption of the business of the House of Commons. Specifically, I've instructed the House authorities to undertake such steps as are necessary to ensure that the House of Commons sits tomorrow and that it does so at eleven thirty AM (10:30 GMT)."

ASSOCIATED PRESS

London - 24 September 2019

4. "Anti-government protester wearing a Boris Johnson puppet head, holding a placard reading (English) "Boris Johnson guilty."

5. SOUNDBITE (English) Jacob Archbold, 21-year-old anti-Brexit protester:

"They need to get back in and start debating Brexit. It's the big issue of the day, we are in a national crisis right now, and we leave the European Union in just over a month so we need to get back in there and start talking about it because if we don't then we're gonna have some big problems, so great ruling today and hopefully we're gonna be able to get back in there and get talking about Brexit."

6. Various of pro-Brexit protesters holding banner reading (English) "Brexit Now"

7. SOUNDBITE (English) Michael McFadden, Pro-Brexit protester:

"You know I'm not trying to be diplomatic, I'm just trying to be realistic, it's not winning or losing, what happens here today we are all gonna lose from it and (UK Prime Minister Boris) Johnson and the Tory party they all have destroyed themselves, there will be no Tory party after this. (Former UK Prime Minister) Theresa May just made us look a bunch of fools and we are not a bunch of fools. The fact that we don't riot around the streets, yet, doesn't mean we are afraid to."

8. Pro-Brexit protesters chanting "We love Boris"

In a major blow to Prime Minister Boris Johnson, Britain's highest court ruled Tuesday that his decision to suspend Parliament for five weeks in the crucial countdown to the country's Brexit deadline was illegal.

The unanimous, strongly worded Supreme Court judgment declared the order to suspend Parliament "void and of no effect."

The court found that Johnson acted to limit debate on Britain's impending departure from the European Union in violation of Parliament's constitutional role.

House of Commons Speaker John Bercow welcomed the historic verdict and said Parliament would resume its business Wednesday morning.

There will not be a Prime Minister Questions session in Parliament on Wednesday because Johnson is in New York for the U.N. General Assembly.

An anti-government protester outside the court welcomed the ruling and said MP's should go back to Parliament as soon as possible.

"We are in a national crisis right now, and we leave the European Union in just over a month so we need to get back in there and start talking about it because if we don't then we're gonna have some big problems," said Jacob Archbold.

Pro-Brexit demonstrators, meanwhile, chanted slogans of support for Johnson.

But Brexit supporter Michael McFadden also said that Johnson and the Conservatives had "destroyed themselves" and accused former Prime Minister Theresa May of making Brexit backers "look a bunch of fools and we are not a bunch of fools."

The landmark decision immediately prompted calls for Johnson to quit.

He has not yet commented on the ruling but had said earlier that he would comply with the court's decision.

London - 24 September 2019

1. Various of anti-government protester wearing a Boris Johnson puppet head, holding a placard reading (English) "Boris Johnson guilty."

2. SOUNDBITE (English) Jacob Archbold, 21-year-old anti-Brexit protester:

"Well, Parliament should come back and sit, I have seen already a few photos of MPs already sitting back in the House of Commons and, you know, they need to get back in and start debating Brexit. It's the big issue of the day, we are in a national crisis right now, and we leave the European Union in just over a month so we need to get back in there and start talking about it because if we don't then we're gonna have some big problems, so great ruling today and hopefully we're gonna be able to get back in there and get talking about Brexit."

3. Various of pro-Brexit protesters holding banner reading (English) "Brexit Now"

4. SOUNDBITE (English) Michael McFadden, Pro-Brexit protester:

"You know I'm not trying to be diplomatic, I'm just trying to be realistic, it's not winning or losing, what happens here today we are all gonna lose from it and (UK Prime Minister Boris) Johnson and the Tory party they all have destroyed themselves, there will be no Tory party after this. (Former UK Prime Minister) Theresa May just made us look a bunch of fools and we are not a bunch of fools. The fact that we don't riot around the streets, yet, doesn't mean we are afraid to."

5. Various of pro-Brexit protesters

6. Protesters chanting pro-Boris Johnson chant UPSOUND (English): "We love you Boris, we do, oh Boris we love you."

A law analyst has said Britain's Supreme Court could request a Brexit extension on behalf of the government, if Prime Minister Boris Johnson doesn't abide by a law to seek a three-month delay.

Last week, members of parliament voted in favour of the government asking the European Union for the delay if no agreement is reached before October 31.

The law was rushed through Parliament before its suspension for five weeks.

The country's Supreme Court is set to decide on Tuesday whether the suspension, which was ordered by Johnson, is legal, after Scotland's highest civil court ruled the prorogation unlawful.

Steven Peers, professor of law at Essex University told the Associated Press that the Court is likely to support the government's Brexit plans "with some limits."

On Monday, Johnson will meet European Commission President Jean-Claude Juncker for the first time in an attempt to renegotiate a Brexit deal.

London - 16 September 2019

1. Various exteriors of British Parliament

2. Setup of Steven Peers, professor of law at Essex University:

3. SOUNDBITE (English) Steven Peers, professor of law at Essex University:

"Well what we've seen for the last six weeks or so is that the government, so Mr (British Prime Minister, Boris) Johnson, keeps saying that he thinks he's likely to get a deal and that they're moving towards a deal. But the signs from the EU, more or less seems, most of them to say that we're not moving much towards a deal. So, unless that somehow radically changes that's what I'd expect to sort of come out from today. Although everyone sort of jumps on what other people says and will take one word or one sentence out of what Mr (European Commission President, Jean-Claude) Juncker says and maybe the next five sentences, in order to say that he thinks we're about to do a deal. But you never know it's always possible that there's been work behind the scenes that we don't all know about that is moving us towards a deal. I wouldn't absolutely rule it out."

4. Cutaway of Peers' hands

5. SOUNDBITE (English) Steven Peers, professor of law at Essex University:

"Well I think lawyers tend to be conservative and the conservative approach, with a "small c," would be to say well let's not upset the traditional rule that governments can choose to suspend Parliament when they like. But then, the counter argument is that the government's doing more than usually suspending Parliament for just a few days here or there, it's doing it at a crucial period to stop Parliament challenging it over Brexit. The reasons it's given don't really hold up to close scrutiny. According to many people who adhere to the press it might just prorogue (suspend) Parliament again if it can. So, those are the concerns that the counter arguments have and maybe the judges will take them into account."

6. Cutaway of Peers

7. SOUNDBITE (English) Steven Peers, professor of law at Essex University:

"Well no one can predict anything. I mean the Supreme Court may or may not rule against the government. Labour MPs (Members of Parliament), may or may not. The DUP (Democratic Unionist Party) may or may not switch in sufficient numbers to pass a deal, they may or may not be successful in a deal. I mean, I think the more likely scenario is the Supreme Court supports the government with some limits, on maybe what it can do in the future and the government doesn't get a deal or doesn't get it passed. So we move into a scenario, of whether it's really going to ask for an extension as the law requires it to do, to ask for an extension of EU membership. I mean, I don't think anyone should be certain about their predictions."

8. Various exteriors of Parliament

9. SOUNDBITE (English) Steven Peers, professor of law at Essex University:

"Well, there are people who've already gone to court to try and get the law enforced, which perhaps might mean the court itself delivering a notice to the EU on behalf of the government that is requesting an extension. It might mean civil servants are ordered to act on behalf of the government, in order to request an extension or you could try and enforce the law directly against Boris Johnson – if he refuses that's contempt of court, which could mean jail time. But I think that's kind of drastic, the courts are more likely to try and find a way to do it without locking anyone up."

10. Various exteriors of Parliament

11. Pan-left from London Bridge to Parliament

Scotland's First Minister Nicola Sturgeon on Tuesday said she was "disappointed" after Britain's Supreme Court ruled that Scotland, Wales and Northern Ireland will not need to be consulted before starting the process of leaving the European Union.

Speaking in Edinburgh, Sturgeon said, despite the ruling, that it was the UK government's "political obligation...to listen to the devolved administrations."

She also welcomed the news that MPs will vote on the triggering of Article 50.

++SOUNDBITES SEPARATED BY BLACK FRAMES++

POOL

Edinburgh - 24 January 2017

1. SOUNDBITE (English) Nicola Sturgeon, Scotland's First Minister:

"Well I welcome the Supreme Court ruling that an act of parliament is required in the House of Commons before the triggering of Article 50. I think that ruling is an indictment of a UK government that thought it could press ahead without any reference to Parliament whatsoever. So it's now vital that parliament gets the chance to debate and decide upon, not just the triggering of Article 50 but I think the terms of the negotiating position as well, and SNP MPs will seek to work with others to stop a hard Brexit in its tracks."

++BLACK FRAMES++

2. SOUNDBITE (English) Nicola Sturgeon, Scotland's First Minister:

"Scotland voted against Brexit and therefore I think it is inconceivable that SNP MPs would vote for the triggering of Article 50. But I think it's important that the House of Commons and parliament is involved not just in that narrow question whether to trigger Article 50 but also the terms of the negotiations. The Prime Minister set it last week, a path towards the hardest of hard Brexits. I don't believe there's a majority for that in the House of Commons and I certainly don't believe there's majority for that across the country so this is an opportunity for the House of Commons to assert itself and to have a say not just on the narrow question but on the broader terms of negotiations as well."

++BLACK FRAMES++

3. SOUNDBITE (English) Nicola Sturgeon, Scotland's First Minister:

"I am disappointed at the Supreme Court ruling about the rule of the devolved administrations and I think it raises a really important question for the UK government after the Smith Commission following the independence referendum. They were at great pains to see that the Sewel Convention was to be embedded in legislation and therefore that it was taking on a more important role in the devolved arrangements. Now, what was the point of embedding it in legislation if it's not legally enforceable? I think that commitment from the UK government today has been shown to be not worth the paper it's written on. That said the court is very clear, that Brexit will touch upon the devolved competencies of the devolved administrations and recognises the importance of Sewel as a political convention. So I think that there's still a political obligation for the UK government to listen to the devolved administrations, we will certainly bring forward a legislative consent motion because I think it's important that the Scottish Parliament has the right to vote on whether or not it is prepared to consent the triggering or not of Article 50."

++BLACK FRAMES++

4. SOUNDBITE (English) Nicola Sturgeon, Scotland's First Minister:

"But there's nothing in the Supreme Court's ruling that's says that Sewel Convention should be ignored completely as a political convention. Clearly Brexit impinges upon the devolved competencies, not just of the Scottish parliament but the Welsh Assembly and the Northern Irish Assembly, as well. And I think it's a matter of democratic principle that the Scottish parliament on such a big fundamental issue with so many implications for the devolved settlements should have a say on whether or not it consents to the triggering of Article 50. So we will bring forward a motion that allows the Scottish Parliament to do that and I will then hope that the UK government would pay attention to it."

++BLACK FRAMES++

5. SOUNDBITE (English) Nicola Sturgeon, Scotland's First Minister:

"I have made very clear that that option is very very much on the table and as I have said before with every day that passes right now it's becoming clearer that Scotland's voice cannot and is not able to be heard within the UK on this question. That raises big issues. I have set down a path of process of exhausting and exploring all options. I will continue to do that but be in no doubt that I think the decision is looming for Scotland. Are we prepared to allow our future to be dictated by a Westminster government that's gone down a path I think the majority of people in Scotland do not want to go down or are we going to take our futures in our own hands?"

++ENDS ON SOUNDBITE++

Campaigners representing the rights of UK citizens living and working in the European Union said they were "delighted and relieved" by Tuesday's ruling at the Supreme Court on the process of leaving the EU.

Britain's government must get parliamentary approval before starting the Brexit process, the court ruled, potentially delaying Prime Minister Theresa May's plans to trigger negotiations by the end of March.

John Shaw, spokesperson for campaign group Fair Deal for Expats, said "proper parliamentary scrutiny now offers the best chance for our circumstances to be considered in the lead up to the Brexit negotiations".

He also urged the government not to use the EU expatriate community as "bargaining chips" but to ensure "hard guarantees are put in place about what the future holds for such a large number of ordinary people"

UK POOL

London - 24 January 2017

++SOUNDBITES SEPARATED BY BLACK FRAMES++

++AUDIO AS INCOMING++

1. SOUNDBITE (English) John Shaw, Fair Deal for Expats campaign group spokesperson:

"We are delighted and relieved by the decision of the Supreme Court today. There can now be proper control by the MPs the British people elect over the process of the UK leaving the EU. Together with 3 million nationals of other European countries who live here, we are the people who are most profoundly affected by all of this. Everything people in Britain take for granted in their daily lives rests for us on our being EU citizens."

++BLACK FRAMES++

2. SOUNDBITE (English) John Shaw, Fair Deal for Expats campaign group spokesperson:

"Proper parliamentary scrutiny now offers the best chance for our circumstances to be considered in the lead up to the Brexit negotiations. This is the human side of Brexit. We would urge the government not to use us as bargaining chips. We will be calling on the government and the European Commission to ensure hard guarantees are put in place about what the future holds for such a large number of ordinary people. We ask that governments across the EU do the same."

++ENDS ON SOUNDBITE++

The lead plaintiff in the British Supreme Court case said on Tuesday that she was happy with the ruling because it provides the legal foundation to trigger Brexit.

Gina Miller spoke shortly after the Supreme Court announced in a majority 8-3 decision that the government must get parliamentary approval before starting the process of leaving the European Union.

Miller also said that the case was about the legal process, not politics.

British Attorney General Jeremy Wright said that the government will comply with the ruling, and that a statement will be made in Parliament later.

The court also unanimously decided that there's no need to consult Scotland, Wales, Northern Ireland on Brexit.

Tuesday's ruling raises hopes among pro-EU politicians that they will be able soften the terms of the U.K.'s withdrawal from the bloc.

British Prime Minister Theresa May wanted to use centuries-old powers known as royal prerogative to invoke Article 50 of the EU treaty and launch two years of exit talks.

++AUDIO QUALITY AS INCOMING++

UK POOL

London - 24 January 2017

1. Lead plaintiff Gina Miller exiting court

2. SOUNDBITE (English) Gina Miller, Lead plaintiff: ++AUDIO AS INCOMING++

"Good morning, today eight of the 11 supreme judges upheld the judgment handed down by the High Court in November, in a case that went to the very heart of our Constitution and how we are governed. Only parliament can grant rights to the people and only parliament can take them away. No prime minister, no government, can expect to be unanswerable or unchallenged. Parliament alone is sovereign. This ruling today means that MPs we have elected will rightfully have the opportunity to bring their invaluable experience and expertise to bear in helping the government select the best course in the forthcoming Brexit negotiations, negotiations that will frame our place in the world and all our destinies to come."

++BLACK FRAMES++

3. SOUNDBITE (English) Gina Miller, Lead plaintiff:

"There is no doubt that Brexit is the most divisive issue of a generation, but this case was about the legal process, not politics. Today's decision has created legal certainty based on our democratic process and provides the legal foundations for the government to trigger Article 50."

++ENDS ON SOUNDBITE++

UK Brexit Secretary Stephen Barclay said Thursday that his government will respect the outcome of an expected ruling by Britain's top court on whether Prime Minister Boris Johnson acted unlawfully when he suspended Parliament.

Johnson sent lawmakers home until 14 October, and his opponents claim he did it to prevent them scrutinizing his plan to take Britain out of the EU at the end of next month, with or without a divorce deal.

Speaking during a visit to Madrid, Barclay said the government would "abide" by the Supreme Court's ruling.

The court was hearing final arguments Thursday. Judges were set to hear from a lawyer for the former prime minister, John Major, who is among those challenging the decision by Johnson, one of his successors as Conservative leader.

Opponents have also accused the prime minister of misleading Queen Elizabeth II, whose formal approval was needed to suspend the legislature.

The government says the suspension is routine and not motivated by Brexit, and argues that judges should not interfere in politics.

Madrid - 19 September 2019

1. UK Brexit Secretary Stephen Barclay entering breakfast meeting with Spanish business leaders

2. Conference sign

3. Wide of Barclay

4. SOUNDBITE (English) Stephen Barclay, UK Brexit Secretary:

"And it is absolutely the correct process that on these matters, then the Supreme Court will form a view and I await that judgement and we of course as a government will abide by it."

5. Camera

6. SOUNDBITE (English) Stephen Barclay, UK Brexit Secretary:

"This was a clear democratic decision of the British people (EU referendum), it is damaging, I think, for democracy if people start to say they will pick and choose which democratic votes they adhere to, I don't think that's what politicians should do so it is important that we deliver on the result. There is time from the (European) Council to the 31st of October. And parliament, there is one thing as the minister for Brexit I can assure you of is parliament has not had a shortage of time to discuss the issue of Brexit."

7. Attendees

8. SOUNDBITE (English) Stephen Barclay, UK Brexit Secretary:

"The UK government abides by the law, the ministerial code requires ministers, including myself to abide by the law, and of course we will abide by the law. Now that it is not to say that we won't look at it closely and test exactly where we are."

9. Wide of Barclay

British Prime Minister Boris Johnson faces a wait for a ruling from the UK's highest court over his advice to the Queen to suspend Parliament for five weeks.

The Supreme Court in London has been asked to determine whether the prorogation move - which has closed down Parliament until October 14 - was unlawful.

A panel of 11 justices heard appeals over three days arising out of separate legal challenges in England and Scotland, in which leading judges reached different conclusions.

At the close of the unprecedented hearing on Thursday, the court's president, Brenda Hale, said the 11 judges would give their ruling early next week.

Lawyer for Scottish National Party MP, Joanna Cherry, one of a group of Scottish MPs who took legal action against the government, said outside court that both sides of the Brexit divide should be worried about the prime minister suspending parliament "as an inconvenience."

"This is not an issue about Brexit. This is an issue about who holds power in this country," Jolyon Maugham said.

London - 19 September 2019

1. Exteriors of UK Supreme Court with media gathered outside

2. Close of court building

3. Various of media outside Supreme Court

4. Brexit supporter holding a 'We Voted Leave' placard

5. Protesters against suspension of parliament gathered outside Supreme Court

6. Brexit supporters holding placards and union jack umbrella

7. Protestors holding a banner reading (English) "Have a nice long holiday folks. Don't come back until Nov 1st Thank you xxx 17.4 million people"

8. Media gathered outside the Supreme Court

9. Transparency activist who filed a case against the suspension of parliament, Gina Miller, leaving court with others

10. Scottish National Party MP, Joanna Cherry, one of a group of Scottish MPs who took legal action against the government, and her lawyer Jolyon Maugham walking out of court

11. The Supreme Court sign

12. SOUNDBITE (English) Joanna Cherry, Scottish National Party MP:

"I would like the court to make as clear a statement as possible as to what should follow. In a normal functioning democracy one would expect the prime minister to obey what the Supreme Court says. But we are not currently in a normal functioning democracy. We're in a democracy, in adverted commas, where a prime minister with no majority has suspended parliament because it was getting in his way. So I would hope that the UK Supreme Court will be as clear as they possibly can be about the consequences of their decision, should they find in our favour."

13. Police gathered outside court

14. SOUNDBITE (English) Jolyon Maugham, Joanna Cherry's lawyer:

"All of us, whatever side of the Brexit divide we are on, should be worried about a world in which a prime minister can suspend parliament as an inconvenience. Those who support Boris Johnson's actions at the moment should be asking themselves the question, how they would feel about a future Labour prime minister, perhaps Jeremy Corbyn, who did not any longer want to be subjected to the constraints that parliament might face upon his actions. How would they feel about this? This is not an issue about Brexit. This is an issue about who holds power in this country. Is it Parliament elected by the people or is it a leader elected by a tiny number of members - self-selecting members - of a particular political party?"

15. Public lawyer from Oxford University, Stefan Theil, using his mobile phone

16. SOUNDBITE (English) Stefan Theil, Public lawyer from Oxford University:

"Because it is the case that Parliament is now prorogued there are certain things that it cannot do anymore. The most important thing is to hold the government to account and it's suggested that there would be a possibility for a - hypothetically speaking - for a prime minister to prorogue Parliament in order to get rid of the army or to prorogue Parliament when it becomes apparent that he or she is going to lose a motion of no confidence and suggested that these examples demonstrate that the principle really has to be that prorogation has to be strictly controlled by the courts. There needs to be anxious interrogation of the reasons for prorogation when it touches on these fundamental constitutional principles."

17. Cutaway of Theil's hands

18. SOUNDBITE (English) Stefan Theil, Public lawyer from Oxford University:

"So potentially very far reaching. So depending on what the courts end up deciding it could mean that the Prime Minister unlawfully prorogued Parliament and that Parliament could sit again. It could also mean that they leave it at a declaration of unlawfulness and don't take any further action, which would then have political repercussion. It's very hard to say at this stage."

19. Exterior of Supreme Court

20. SOUNDBITE (English) Stefan Theil, Public lawyer from Oxford University:

"It looks really bad for Boris Johnson I think if it's found to be unlawful. This is really an unprecedented case. It really hasn't happened before that prorogation has been before the courts like this and it would be bad for any prime minister I should think."

21. Security guard outside court

22. Exteriors of Supreme Court