The deputy prime minister gave his verdict at private meeting of six MPs at his Whitehall office on Tuesday, according to Harry Cohen, MP for Leyton and Wanstead.

Mr Cohen said: “He was talking in the context of the ‘road map’ in the Middle East. He said he only gave support to the war on Iraq because they were promised the road map. But he said the Bush administration had been crap on that.

“We all laughed and he said to an official, ‘Don’t minute that.’ We also had a laugh when he said old Bush is just a cowboy with his Stetson on.”

Others present at the meeting, including Muslim MPs and MPs critical of the government’s foreign policy, have said that they cannot recall him using the term.

One of those present told The Independent newspaper: “There was a very robust exchange of views.”

Mr Cohen said that he stood by his account.

In a statement last night, Mr Prescott stopped short of a total denial. He said: “This is an inaccurate report of a private conversation and it is not my view.”

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