President Bush gave Tony Blair a final chance to pull out of the Iraq war coalition because he feared for the survival of the British Government, Blair Unbound reveals.

Despite the urgings of his aides and his precarious position within the Labour Party, Mr Blair spurned the chance, and that later offered by Donald Rumsfeld, the US Defence Secretary, because he believed in military action if diplomacy failed.

The book quotes Condoleezza Rice, who was then the US National Security Adviser, speaking about a telephone call between Mr Bush and Mr Blair on March 9, 2003, only days before the war began. Efforts to win a second UN resolution, the bottom line for many Labour MPs in London, were on the point of failing and the White House was worried about Mr Blair’s position.

“I remember standing in the Oval Office,” Dr Rice recalled, “and the President said ‘We can’t have the British Government fall because of this decision over war’. He said: ‘I have to tell Tony that he doesn’t have to do this . . . I’m going to call him right now’. ”

Dr Rice recalls that he told Mr Blair: “What I want to say to you is that my last choice is to have your Government go down. We don’t want that to happen under any circumstances. I really mean that.”

Mr Blair had replied: “I said I’m with you. I mean it.”

Times Recommends

• Charles blazes trail as sun king
• Thalidomiders win payout 50 years on
• Libel gag on talk of 'medical hurricane'