At his weekly question and answer session in the House of Commons, Blair insisted that "in relation to the allegations that have been made, there is not a shred of truth" in them.

Asked if he would give evidence to an investigation by the Foreign Affairs Select Committee, the prime minister told deputies: "In accordance with convention, I will not attend that committee," although Foreign Secretary Jack Straw would.

However, Blair said he would "cooperate in any way at all" with a separate inquiry by parliament's joint intelligence and security committee -- which meets behind closed doors, and whose reports are subject to censorship by Downing Street.

Blair has for weeks been forced to defend himself against charges made by the media and seized upon by the opposition that his office tried to make Saddam Hussein's regime appear more menacing by embellishing a dossier on weapons of mass destruction, published in September, before the US-led war against Iraq.

Unnamed sources told BBC radio that a line in the government document -- that Iraq could deploy chemical or biological weapons in just 45 minutes -- was inserted at Downing Street's behest despite the reservations of spy chiefs.

WAR.WIRE