Magen David Adom UK has launched a campaign to demand Red Cross access to kidnapped soldier, Gilad Shalit.
The British branch of the Israeli ambulance charity, which is also part of the International Committee of the Red Cross (ICRC), is urging supporters to sign a petition calling on Hamas, under the Third Geneva Convention, to allow the Red Cross to visit Sergeant Shalit.
Almost 11,000 have so far signed the petition, addressed to Tony Blair in his capacity as Quartet representative.
MDA UK chief executive Eli Benson said: "This is something we should have done a long time ago. The Red Cross has been trying their utmost and they just haven't been allowed to see him.
"We thought we should put on different pressure. This will be a good route because we deal with Red Cross agencies all over the world.
"It's not political, it's purely humanitarian."