Renewed doubt over Iraq's alleged weapons of mass destruction (WMD) has recharged questions about Mr Tony Blair's judgment and integrity in advance of Wednesday's publication of the Hutton report, write Frank Millar in London, and Conor O'Clery in New Hampshire
The British Prime Minister, however, has again insisted he has "absolutely no doubt" that the intelligence he received about Iraq's weapons was genuine, and that "in the end we will have an explanation".
Former foreign secretary Mr Robin Cook, who quit the government over Iraq, has demanded that Mr Blair "admit defeat" on the issue following Mr David Kay's resignation from the leadership of the Iraq Survey Group and his conclusion that Iraq had no large-scale weapons production programme during the 1990s and no large numbers of WMD available for "imminent action".
The US Secretary of State, Mr Colin Powell, who made the case at the United Nations for toppling Saddam Hussein, meanwhile admitted on Saturday that Saddam's government may not have possessed banned weapons.
Conservatives and Liberal Democrats have signalled they will intensify their demands for a full judicial inquiry into the build-up to the war, regardless of Lord Hutton's conclusions on the circumstances leading to the death of former government scientist Dr David Kelly.
Mr Blair acknowledged yesterday that his job was "at risk", in a week which combines Lord Hutton's report with the serious possibility of a Commons defeat tomorrow over university fees. At the same time he told the Observer he had "every intention" of remaining in his job come the end of what promises to be the most testing week of his premiership.
Downing Street is confident that Lord Hutton will clear Mr Blair of lying over the so-called "naming strategy" by which Dr Kelly was identified as the source for BBC claims that Number 10 "sexed up" the government's controversial weapons dossier against intelligence advice. The permanent secretary at the Ministry of Defence, Sir Kevin Tebbit, told the Hutton inquiry that "a policy decision on the handling of this matter" had not been taken until a meeting at which Mr Blair presided on July 8th last year.
And while conventional wisdom at Westminster is that the Defence Secretary, Mr Geoff Hoon, will be the most likely cabinet casualty over the Kelly affair, Mr Blair also told the inquiry:
"In the end I have full responsibility for the decisions that are taken ... Responsibility is mine in the end. I take the decisions as Prime Minister."
As Mr Powell appeared to cast further doubt on whether the alleged WMD would ever be found, Mr Cook said:
"It is becoming undignified for the Prime Minister to continue to insist that he was right all along when everybody can now see he was wrong."
Former defence minister Mr Lewis Moonie, who was part of Mr Blair's team at the time of the conflict, said the government may soon be forced to concede it was wrong on its main justification for war.
Yesterday's Sunday Telegraph claimed Mr Blair would escape personal criticism over the events surrounding Dr Kelly's public exposure and subsequent presumed suicide. Its lead story quoted "the Prime Minister's aides" as confirming that Mr Blair had not received a letter from Lord Hutton warning him of potential criticism in the report, and said others who had received such letters included Mr Hoon and Mr Blair's former communications director, Mr Alastair Campbell.
However, an informed government source told The Irish Times the report appeared to be based on the mistaken assumption that Lord Hutton had followed the procedure he adopted last summer when he wrote in advance to those being recalled before his inquiry, advising them of the areas on which they would be subject to further questioning.