Although no British ship has joined the ill-fated flotilla from Athens to Gaza, this week activists in the UK have been lobbying Prime Minister David Cameron and the Greek ambassador to "guarantee their safe passage".

Six pro-Palestinian activists from the Free Gaza Movement handed in a letter at the gates of 10 Downing Street, which was taken by security guards and forwarded to the Petitions Office.

The letter, written by Guardian journalist Ewa Jasiewicz, asked Mr Cameron "to notify the Israeli government unequivocally that it should not interfere with the upcoming Flotilla" and to "guarantee the rights of UK citizens and other civilians safe passage on the high seas."

Later, protesters attempted to deliver a letter to the Greek Ambassador Aristidis Sandis, to demand that the ships be allowed to leave Athens, signed by groups including Palestine Solidarity Campaign, Friends of Al Aqsa and Action Palestine.