“Everyone sensed what it was about,” said a member of Campbell’s staff. “Let’s face it, it’s been an open secret for months that Alastair was going to quit.”

Looking slightly sheepish, eyes glancing to the floor, Blair’s director of strategy and communications confirmed: “It won’t come as any great surprise to you, but I’m announcing today that I am leaving Downing Street. Most of you know that I’ve been thinking about it for some time.”

All the same, there was disbelief that he was really going at last. But a cheeky Blair aide broke the tension: “Will there be a minute’s silence at Burnley football club?”

The throng burst into nervous laughter. Campbell has been a loyal follower of the northern club since childhood. His passion for the team is tribal and matched only by his kinship with Tony Blair and new Labour. All too often both Burnley and Blair have looked like the junior partners in the relationship.

Campbell has been there 24/7 for nine years now as Blair’s spokesman, confidant, rottweiler, chief adviser, right-hand man and friend. He has told Blair what to say and how to say it, travelled with him several times around the globe and cultivated a loyal following for him among MPs and the press.

He has been dubbed “the real deputy prime minister”, personally reprimanded cabinet ministers for stepping out of line and spawned an industry of impersonators. And he is at the heart of the still unresolved crisis threatening the Blair premiership, the apparent suicide of Dr David Kelly.

So there was more disbelief mixed with déjà vu when his resignation was announced to the public that afternoon.

After a week of unprecedented drama at the Hutton inquiry into Kelly’s death, this was the last thing predicted. Although Westminster and the political media have written Campbell’s political obituary many times over the past few months, insiders still asked themselves: why now? And how would the prime minister survive without this irreplaceable hatchet man?

CAMPBELL says he has thought about leaving Downing Street for nearly two years. He had an idea to go six months after the 2001 general election, but September 11 and the war on terrorism made that impossible.

Returning from his summer holiday in Provence last year, he suggested that he had outlived his usefulness and was becoming too much “the story”, but the prime minister asked him to stay on. The fervour over Iraq was just taking hold in the Labour party, the wider public was beginning to believe that war was imminent and there was a dossier to be produced to prove the case against Saddam Hussein.

In April, once the war was won, Campbell told Blair that he was determined to go. The prime minister was preparing for the arrival of President George Bush at Hillsborough Castle when Campbell dropped the news that he wanted to leave along with his girlfriend, Fiona Millar. She had become disillusioned as Cherie Blair’s press “minder” — a feeling shared by Campbell, who during the row over Carole Caplin, Cherie Blair’s lifestyle guru, had allegedly briefed against the prime minister’s wife.

In May, Campbell went so far as to draft the press release announcing his departure. Agonisingly, however, next day Andrew Gilligan’s BBC report about the “sexed-up” Iraq dossier triggered the current political crisis and put the resignation on hold again.

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