The BBC said today senior figures "right at the top" of the British government no longer believed weapons of mass destruction would be found in Iraq.
The report looks set to deepen divisions over whether the war was justified, as well as restart a row between the British government and the state-funded BBC over Iraq coverage.
"They [senior ministers] do think there were weapons there . . . but the actual weapons, the tubs of evil stuff, the rusting missiles . . . belief that they will actually be available, that is trickling away very fast," BBC political editor Mr Andrew Marr said on television news.
"The best explanation going around at the moment is that some time shortly before the war Saddam Hussein destroyed them or hid them beyond discovery".
A Downing Street spokesman dismissed the BBC report, however, saying the Mr Blair stood by his earlier comments. "The BBC talks about senior ministers, well Tony Blair said on Tuesday he believed the weapons would be found and it doesn't get much more senior than that," he said.
The issue of Iraqi weapons has sparked fierce debate on both sides of the Atlantic, but Mr Blair has had to bare the brunt in recent weeks. Opinion polls suggest the British public is no longer convinced of the case for war and members of parliament from all parties want proof of weapons to justify the campaign.
Speaking to a parliamentary committee on Tuesday, Mr Blair denied misleading Britain over the case for war and said he was in no doubt evidence of banned weapons programmes would be found.
US President George W. Bush said last night he remained confident the Iraq war was right, even though the White House acknowledged it had been a mistake to accuse Saddam Hussein of trying to buy uranium from Niger.
US Defence Secretary Mr Donald Rumsfeld also said the United States did not go to war with Iraq because of dramatic new evidence of banned weapons, but because it saw existing information in a new light after the September 11th attacks.
Weeks earlier, his deputy Mr Paul Wolfowitz said the US decision to stress the weapons threat as a reason for war was taken for "bureaucratic" reasons.