"I watched the way that the British built their case, and it was a disarmament case as best I could see it," said Joe Wilson, whose wife Valerie Plame saw her role as a CIA agent leaked to the media.

The leak occurred after Wilson publicly questioned Bush's rationale for going to war against Iraq.

"Mr Blair came to the US when Mr Bush was talking about regime change, and when he left Mr Bush started talking about disarmament as the objective," Wilson told BBC Radio.

"Mr Bush went to the United Nations, I think that that had a lot to do with the influence of the British," Wilson said.

"I think that Mr Blair really thought that he was getting involved in a disarmament campaign, which was all to the good. I fully supported that," said Wilson, who was charge d'affaires in Baghdad in the run-up to the 1991 Gulf war and later served as an ambassador in Africa.

"I think at the end of the day he was doubled-crossed by the regime change crowd in Washington," he said.

The CIA sent Wilson to Niger in 2002 to investigate claims Saddam Hussein tried to buy unprocessed uranium for nuclear bombs. He concluded that it was highly doubtful the transactions ever took place, but Bush asserted in his 2003 State of the Union address that Iraq tried to purchase uranium.

Wilson then wrote an opinion piece challenging Bush's rationale for going to war against Iraq, and soon thereafter his wife's identity as a CIA agent was leaked by government officials.

The leaking of Plame's identity in 2003 triggered a political scandal and a federal investigation that resulted in the indictment last month of top White House aide I. Lewis "Scooter" Libby.

White House officials were at odds with the CIA at that point, suspicious that the intelligence agency was downplaying Saddam Hussein's efforts to develop dangerous weapons.