"Let me be clear that the situation in Gaza has to change... Gaza cannot and must not be allowed to remain a prison camp," he said in a speech to a business association during a visit to Turkey.

Speaking later after talks with Turkish Prime Minister Recep Tayyip Erdogan, Cameron defended his harsh description, saying that "even though some progress has been made we're still in a situation where it's very difficult to get in, it's very difficult to get out...

"We've long supported lifting the blockade of Gaza," he said.