Blair goes before the liaison committee -- made up of the chairmen of all the Commons' watchdog select committees -- at 10 am (0900 GMT) just 24 hours after the release of the report from the foreign affairs committee.

It had investigated two dossiers published by Blair's government in the run-up to war -- one of which included a headline-grabbing claim that Iraq could deploy chemical or biological weapons in 45 minutes.

The committee also probed a BBC report in late May quoting an intelligence source who claimed that the dossier published in September was "sexed up" with the 45-minute claim despite doubts among intelligence chiefs.

"We conclude that the 45-minute claim did not warrant the prominence given to it in the dossier, because it was based on intelligence from a single, uncorroborated source," the report said.

"We recommend that the government explain why the claim was given such prominence," it added.

The BBC -- which has come under unusually stiff pressure from Downing Street to either apologize or retract its report -- said it felt "vindicated" by the findings.

Downing Street said it did not accept that Blair misrepresented the case for war to parliament -- a line that he was expected to stick to on Tuesday and again on Wednesday during his weekly Commons question period.

Blair, who was US President George W. Bush's closest ally on Iraq, did not take part in the foreign affairs committee's hearings.

But he has ordered a separate inquiry by the British parliament's intelligence and security committee. Though it usually meets behind closed doors, Blair has promised its findings will be released.

Blair regularly testifies before the liaison committee -- typically doing so in shirt-sleeves -- to field detailed questions on government policy and topical issues.

National newspapers Tuesday portrayed the foreign affairs committee report as a setback for the prime minister, while a poll in The Times suggested a waning of support among Britons for the decision to have gone to war.

The Guardian, which was editorially anti-war, said the committee report laid bare how Blair and his team "struggled" to make the case for war, "because the case was not -- and is still not -- convincing."

The Daily Telegraph, editorially in favor of military action, called for the resignation of Alastair Campbell, one of Blair's closest aides, "an autonomous, unaccountable operator" in the heart of government.

Campbell, chief media strategist at Downing Street, had a central role in preparing both the September dossier and a second document in February that turned out to have been lifted in part from a US post-graduate student's dissertation.

The poll in The Times, conducted last Friday through Sunday, found that 45 percent felt military action in Iraq had been wrong -- compared with 24 percent in April. Forty-seven percent felt it was right.

Asked if Blair had the "leadership qualities needed in a prime minister," 56 percent replied yes. But 54 percent also said they agreed with the statement "I wouldn't trust him further than I could throw him."

WAR.WIRE