Alastair Campbell drafted his resignation statement on 28 May, saying he would leave Downing Street at around the time of Labour's annual conference at the end of September. The following morning, the BBC journalist Andrew Gilligan broadcast his fateful claim on Radio 4's Today programme that No 10 had "sexed up" the Government's dossier on Iraqi weapons.
Mr Campbell became embroiled in his battle with the BBC and his resignation was never announced. Although he could not have known the dispute would end in the death of a government scientist, friends and colleagues regret that his departure was put on hold.
The nadir of Mr Campbell's career came on 18 July when he was told that David Kelly had gone missing. When Dr Kelly's death was confirmed, Mr Campbell knew a speedy departure from Downing Street was inevitable.
One colleague said yesterday: "He was brilliant. But the trouble was, he knew he was brilliant, and he thought he could win one final victory over the BBC." Another No 10 insider added: "With hindsight, it would have been better if he had left earlier, and we should have called a truce with the BBC."
In Mr Campbell's own eyes, the high point of his nine years as Mr Blair's closest aide came when he took a telephone call at a rally during the 1997 general election campaign: the next morning, The Sun would endorse Labour.
Winning the support of the paper that had crucified Neil Kinnock in 1992 was the culmination of a long campaign to tame the tiger of the Murdoch press. "Never again" was Mr Campbell's maxim after he agreed to become Mr Blair's press secretary in 1994, when the new Labour leader pursued him across France to twist his arm.
He was part of a remarkably small band with Mr Blair, Gordon Brown and Peter Mandelson who took Labour by the scruff of the neck and transformed it into a party that won two massive general election victories.
He was accused of being a "bully" when he handled the media, of which he said privately: "The media is very good at giving it out, but not very good at taking it." Friends say this is a one-dimensional portrait of a clever, witty, family man who would much rather travel hundreds of miles to watch his beloved Burnley football team play rather than spin another pro-Blair tale to the tabloids. His staff at No 10 say he was a "fantastic" boss who was loyal and protective towards his team.
The son of a Scottish vet, Mr Campbell was known as "Jock" at his comprehensive school in Leicester because he played the bagpipes, something he was later to do at Downing Street parties. After reading modern languages at Cambridge, he penned pornographic articles for Forum magazine under the byline "The Riviera Gigolo".
At the age of 29, as news editor of the now-defunct Sunday Today newspaper, he suffered a nervous breakdown. Admitting he was out of his depth, he recalled: "I hit the bottle pretty hard, got completely manic and cracked." He said his breakdown felt "like a piece of glass cracking into thousands of pieces inside your head". Since recovering, with the sterling support of his partner, Fiona Millar, he has drunk nothing stronger than tea.
Mr Campbell is convinced that what he calls his "24-carat crack-up" made him a much stronger person. Politics was always in his blood and he admitted he was a propagandist rather than a journalist.
While working at the Daily Mirror, he acted as an unofficial adviser to Mr Kinnock, who recalled: "He did everything to excess playing the bagpipes, smoking and drinking." He said that Mr Campbell overcame his problems with "extraordinary single mindedness".
Ms Millar, with whom he has three children, admitted recently: "Alastair doesn't do anything by half measures." It was she who suggested that he run this year's London Marathon. Mr Campbell trained obsessively, running to Downing Street from his Gospel Oak home. But he also showed his other side, raising nearly £300,000 for Leukaemia Research in memory of his journalist friend John Merritt, who died from the disease.
In his new life, Mr Campbell will do more work for the charity; friends say a more rounded picture of him will emerge when he leaves the trenches of the media battlefield.
The charge of "bullying" extended to civil servants and even ministers. When Labour came to power in 1997, Mr Campbell and Jonathan Powell, Mr Blair's chief of staff, were given special powers to issue orders to neutral officials. "Tony wants" and "Alastair wants" were synonymous. Mr Campbell explained yesterday: "I have no power and never have had independent of the Prime Minister who I serve." In other words, he acted with the full authority of his boss. He became known as "the real Deputy Prime Minister". The myth was also the reality. He in effect sacked Peter Mandelson as Northern Ireland Secretary in a briefing for Westminster journalists during the row over his links with the Hinduja brothers.
Rory Bremner's parody, showing Mr Campbell bossing Mr Blair around, appeared starkly true when a television documentary on the workings of Downing Street captured them up close and personal.
By 2000, Mr Campbell was "becoming the story" the spin doctor's cardinal sin. He withdrew from Downing Street's twice-daily briefings to a backroom role as director of communications. But there was little doubt that he continued to pull the strings. "Spin", Labour's greatest asset in opposition, became its biggest liability in government.
Of course, Mr Campbell would never have pursued his last crusade against the BBC if he he had known where it would end. He was devastated by Dr Kelly's death, and knew that he would face some of the blame for prolonging the dispute.
Mr Campbell's friends now admit that he should have "moved on", as Mr Blair told the Hutton inquiry he wanted to. "By the end, he was out of control," one said.
In the short term, it will be difficult to forget the tragic circumstances surrounding Mr Campbell's departure. The longer term will probably be more favourable.
A QUOTABLE SPOKESMAN
What Alastair Campbell said during his time at Downing Street - and what others said about him:
¿ I simply say, in relation to the BBC story, it is a lie ... that is continually repeated, and until we get an apology for it I will keep making sure that Parliament and people like yourselves know that it was a lie - to the Foreign Affairs Select Committee.
¿ What we don't do is sit around wallowing and navel-gazing. What you do is come out fighting and make your case - after Mr Blair's humiliation at the hands of the Women's Institute.
¿ The day of the bog-standard comprehensive school is over - explaining the Government's plans for more specialist schools.
¿ The day of the daredevil reporter who refuses to see obstacles to getting the truth, and seeing it with his or her own eyes, seems to have died - on reporting of the Kosovo conflict.
¿ We don't do God. I'm sorry. We don't do God - when asked about Mr Blair's religious views.
¿ The Prime Minister is not a gay gangster - responding to attacks by President Robert Mugabe of Zimbabwe.
¿ What becomes very clear the longer you go is that Labour councils look after the paving stones better than the Tory councils - while training for the London Marathon.
¿ You great quivering jelly of indecision - to the Conservative MP Boris Johnson.
¿ Don't worry. He's a reformed drunk- the Prime Minister, explaining to the Russian President, Vladimir Putin, why the teetotaller Mr Campbell was refusing drinks.
¿ I hope you redeem yourself with other sins - Mr Putin to Mr Campbell.Reuse content