David Kay, who stood down yesterday as head of the Bush administration's hunt for weapons of mass destruction in Iraq, said that he did not believe that any stockpiles of such weapons ever existed.
Mr Kay, a former UN inspector, said that most of what was going to be found in the hunt for Saddam Hussein's WMD had already been uncovered. The returning of sovereignty to the Iraqis would make the search more difficult, he added. "I don't think they existed," Mr Kay said, referring to Saddam's alleged stockpiles of chemical, biological and nuclear weapons. "What everyone was talking about is stockpiles produced after the end of the  Gulf War and I don't think there was a large-scale production programme in the Nineties."
Mr Kay's comments will be an embarrassment for the Bush administration. Earlier this week the Vice-President, Dick Cheney, one of Washington's most outspoken hawks who led the rallying cry for war insisting that Saddam possessed WMD, said the outcome of the search was not clear. "I think the jury is still out," he said. "It's going to take ... time to look in all of the cubby holes and ammo dumps in Iraq."
Despite having the resources of more than 1,000 personnel dedicated to the hunt for such weapons, an interim report issued by Mr Kay in October conceded that no weapons had been found, even though there was evidence Iraq had retained the "template" of a weapons programme.
The Bush administration appears determined to continue its public stance that such weapons could be discovered.
Donald Anderson, the Labour chairman of the Foreign Affairs Select Committee, said that Mr Kay's comments posed serious problems for British and American intelligence agencies. "My understanding is that the President and the Prime Minister were acting on intelligence then available [at the time of deciding to go to war]. So this raises very important questions about the quality of that intelligence," he told BBC's Newsnight.
A Downing Street spokesman said: "It is important that people are patient and we let the Iraq Survey Group do its work. Their work is continuing and we should await the outcome of that. Our position is unchanged."
Today the former Foreign Secretary Robin Cook said that Mr Blair must now admit that the Iraq war was a mistake.
Mr Cook said he believed Mr Blair led Britain into the conflict in order to demonstrate to US President George Bush that he was a reliable ally and had been driven by "missionary zeal" and "evangelical certainty".
Mr Cook said on BBC Radio 4's Today programme: "It is becoming really rather undignified for the Prime Minister to continue to insist that he was right all along when everybody can now see he was wrong, when even the head of the Iraq Survey Group has said he was wrong.
"I think it is very important that Tony Blair does concede that there were mistakes made, maybe in all good faith, probably he believed them genuinely, but there were mistakes. Because if we don't face up to the fact that we got it wrong, then we are not going to learn the lessons.
"We have got to drop this very dangerous doctrine under which we went to war of the pre-emptive strike. If there was no threat from Iraq we obviously had no right to carry out a pre-emptive strike to remove that threat. And we better drop that doctrine before somebody else in the world uses it in their own back yard."Reuse content