By Nick Assinder
Political Correspondent, BBC News website
Tony Blair has faced any number of claims about what he did and did not do when he and President Bush were preparing to go to war on Iraq.
The difference with Sir Christopher Meyer's recollections is that he was actually there most of the time.
Sir Christopher Meyer's timing is impeccable
The former UK ambassador to the US witnessed much of the talk first hand and was in a position to see the relationship between the two men develop, and even help it along where necessary.
Inevitably, much of the comment on his book, "DC Confidential", serialised in the Daily Mail and the Guardian, has been about the lead up to and fallout from the Iraq war.
And it does not make happy reading for the prime minister who has already faced claims he failed to exert any real influence over the president and was all too easily swept up in the rush to war.
The prime minister, it is claimed, was so "seduced" by US power that he failed to exert the leverage that was available to him with a president desperate to win allies.
Indeed, the accounts suggest that the prime minister offered such unconditional support to the president, that he effectively negated the influence he may have been able to exert, particularly for the post-war Iraq.
"We may have been the junior partner in the enterprise but the ace up our sleeve was that America did not want to go it alone. Had Britain so insisted, Iraq after Saddam might have avoided the violence that may yet prove fatal to the entire enterprise."
That will serve to reinforce those critics of the prime minister who saw his role as the president's poodle and who, while denying it at home, was reassuring the US that he was in favour of regime change - something else Sir Christopher confirms.
But he rejects the poodle jibes, declaring: "Blair chose to take his stand against Saddam and alongside Bush from the highest of high moral ground.
Ambassador claims Blair backed regime change
"It is the definitive riposte to the idea that Blair was merely the president's poodle, seduced though he and his team always appeared to be by the proximity and glamour of American power."
But he goes on to say: "But the high moral ground, and the pure white flame of unconditional support to an ally in service of an idea, have their disadvantages.
"They place your destiny in the hands of the ally. They fly above the tangled history of Sunni, Shia and Kurd. They discourage descent into the dull detail of tough and necessary bargaining; meat and drink to Margaret Thatcher, but, so it seemed, uncongenial to Tony Blair."
But, apart from throwing some confirming light onto the run-up to the war, Sir Christopher's book also paints a bigger picture of a prime minister taking US presidential politics as his personal template and of a Downing Street machine which had taken all government power into its own hands.
The former ambassador says he discovered very early that, as had been the case with Margaret Thatcher, relations with the US would be controlled by Downing Street with the Foreign Office relegated to second fiddle.
"The Foreign Office never stood a chance. America belonged to Downing Street."
Cherie lost her hairdresser at Camp David
Sir Christopher's memoirs are also littered with anecdotes that throw some light into the smaller corners of the prime minister's lifestyle.
For example, on Alastair Campbell, he says: "My eternal memory of him will always be his standing over Tony Blair, on some flight or other, gesticulating forcefully while the prime minister sat meekly in his seat like a schoolboy under instruction."
And on Cherie Blair, he recalls the occasion after the Blairs had left Camp David and arrived to board their waiting Concorde at Andrews Air Force base in Washington.
"The VIPs and the red carpet were all in place for the brief farewell ceremony.
"Suddenly the cry went up: Cherie's hairdresser is missing! Her French stylist had accompanied us on our mission ......He had been left behind at Camp David. A helicopter brought him post-haste to Andrews as the rest of us kicked our heels."
And on the close relationship between Mr Blair and Bill Clinton, he recalls a visit to a high school in Maryland.
"They were out on stage, It was president and prime minister as rock stars. Give them black pork-pie hats and shades and it would have been the Blues Brothers.
"The screaming was deafening, the adulation total. 'How,' I thought to myself, 'how can you do this and not let it turn your head?'."
As a whole, these memoirs appear to reinforce the already widely-held view of the prime minister as a presidential figure, surrounded by a trusted band of committed and influential advisers to the exclusion of outsiders and who very early on tied himself irrevocably to the White House.
It may well irritate, even infuriate the prime minister, probably the very fact it has been written is enough to do that.
And it will undoubtedly be taken as evidence for their case by the prime ministers' critics of both the war and his wider style of government.
The prime minister has long ago learned to live with that - but the timing of these memoirs is still, to say the least, unfortunate for the prime minister.