Tony Blair told President George Bush that he was solidly" behind US plans to invade Iraq before he sought advice about the invasion's legality and despite the absence of a second UN resolution, according to a new account of the build-up to the war published today. A memo of a two-hour meeting between the two leaders at the White House on January 31 2003 - nearly two months before the invasion - reveals that Mr Bush made it clear the US intended to invade whether or not there was a second UN resolution and even if UN inspectors found no evidence of a banned Iraqi weapons programme. Mr Bush told Mr Blair that the US was so worried about the failure to find hard evidence against Saddam that it thought of "flying U2 reconnaissance aircraft planes with fighter cover over Iraq, painted in UN colours". Mr Bush added: "If Saddam fired on them, he would be in breach [of UN resolutions]". The revelation that Mr Blair had supported the US president's plans to go to war with Iraq even in the absence of a second UN resolution contrasts with the assurances the prime minister gave parliament shortly after. On February 25 2003 - three weeks after his trip to Washington - Mr Blair told the Commons that the government was giving "Saddam one further, final chance to disarm voluntarily". Downing Street did not deny the existence of the memo last night.