A convoy of bringing medicine, food and clothing from the United Kingdom to desperate Gazans reached the blockaded territory on Monday.
The convoy is part of a Gaza aid campaign organised by the Viva Palestina group and backed by UK Member of Parliament, George Galloway.
About 50 British and Scottish volunteers and 100 vehicles carrying aid supplies passed through Egypt's Rafah border crossing, a Hamas border official said.
Galloway said 300 British citizens and 200 Libyans would be entering Gaza.
Other aid, including electrical generators and a fire engine, would enter Israel, where the UK delegation hoped to get it into Gaza through coordination with the International Committee of the Red Cross, the official said.
After entering Gaza, Galloway called the aid "a drop in the ocean," but said the trip was to send a message that "the lifeline from Britain to Gaza is in."
Israel - with Egypt on one side - has enforced a strict blockade of the seaside strip since Hamas took control of the territory in June 2007.
The Israeli government said it allows daily convoys of aid into Gaza and denies that there are shortages of food, fuel or medicine there.
But human rights organisations and the United Nations have repeatedly said that the blockade has caused a humanitarian catastrophe for the impoverished 1.4 (m) million Gazans trapped in the territory.
The crisis was made worse by Israel's devastating three-week military offensive on the Strip earlier this year which killed nearly 1,300 Palestinians, including hundreds of civilians, and left behind an estimated two (b) billion US dollars in damage.