Britain has restated demands for the release of a captured Israeli soldier as he spent his 24th birthday held hostage by Hamas militants.
Gilad Shalit has been in captivity in the Palestinian enclave of Gaza since June 2006, when he was abducted in a cross-border raid.
The Red Cross has been denied access to him for all that time.
The UK Government has backed international calls for the release of the soldier, whose captivity is strongly condemned by Israel.
The Foreign Office spokesman said: "The thoughts of many in Britain are with Gilad Shalit and his family as he spends his 24th birthday in captivity.
"His detention is unjustifiable and unacceptable. The British Government demands his immediate and unconditional release."
Prime Minister David Cameron angered Israel last month by referring to the Gaza Strip as a "prison camp" as he called for an end to the blockade of the territory.
Responding at the time, Israel's ambassador to London, Ron Prosor, pointed to Shalit's ordeal as he insisted that Gaza's problems were the responsibility of Hamas.
"The people of Gaza are the prisoners of the terrorist organisation Hamas. The situation in Gaza is the direct result of Hamas' rule and priorities," Mr Prosor said.
"We know that the Prime Minister would also share our grave concerns about our own prisoner in the Gaza Strip, Gilad Shalit, who has been held hostage there for over four years, without receiving a single Red Cross visit."