LONDON, Jan 6 (Reuters) - An immediate ceasefire in Gaza is possible if arms supplies through tunnels used by Hamas militants are halted, Middle East envoy Tony Blair said on Tuesday.

"I think the position is there are circumstances in which we could get an immediate ceasefire and that's what people want to see," the former British prime minister told BBC radio.

"I think those circumstances focus very much around clear action to cut off the supply of arms and money through the tunnels that go from Egypt into Gaza."

Blair, an envoy for the international groups sponsoring Middle East peace talks, said that his discussions with Israel's prime minister and foreign and defence ministers suggested this was the "one basis" on which it would be possible to secure an immediate ceasefire.

"Otherwise I think you're into a more protracted campaign," he said.

Blair added: "...I think the Egyptians in principle are prepared to do this, they want to do it, they recognise it's in their own interest as well." (Editing by Charles Dick)

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