Tony has to act as if he might quit soon. It's what keeps Gordon going

The idea that Tony Blair is about to step down is as unfounded now as it was three months ago, when the intermittent blaze of speculation was started by his U-turn on a referendum on the EU constitution. The underlying facts - despite what John Prescott said about the plates - have not shifted. They are:

First, this would be the worst possible time for the Prime Minister to go if he has an eye to posterity. After a cruel spring of bad news from Iraq and, this week, after the Butler report on pre-war intelligence failures, quitting would effectively be an admission that he was wrong to take the country to war.

Second, the Labour Party does not need to switch leaders in order to have a chance of winning the next general election, which is what did for Margaret Thatcher in 1990.

Third, plotters cannot get rid of Blair if he does not want to go - that would require a vote at the Labour Party conference, although a vote of no confidence among Labour MPs would also do the trick. Neither is remotely likely.

Fourth, he has not promised Gordon Brown in writing or in front of witnesses that he will go by a certain date. He certainly did not in the Granita restaurant 10 years ago, and people in a position to be so are adamant that he did not at the dinner with Brown at Prescott's Admiralty Arch apartment last November.

What, then, are six cabinet ministers doing, advertising the fact that they have, separately, urged Blair to stay on? Andrew Marr, the political editor of the BBC, reported yesterday that John Reid, Tessa Jowell and Charles Clarke had meetings with the Prime Minister last month, while Patricia Hewitt had written to him. My colleague Andy McSmith had previously reported that Clarke, Charles Falconer and Peter Hain had seen Blair to ask about his intentions. When Andy and I interviewed Clarke on Friday, he said he sought the meeting with Blair because of press speculation, but that he had realised "within 20 seconds" that it was unnecessary, so clear was Blair's determination.

His motive in speaking on the record, and the motive of others who have let their actions be known, may be to try to strengthen Blair by showing that he has the support of his Cabinet. Not only is there a reshuffle coming up, but these are all ministers who, to a greater or lesser extent, have reasons to fear a Gordon Brown premiership. The trouble is that an attempt to kill speculation often only prompts more.

What was unexpected about Marr's report was his claim that Blair had been through "something of a long night of the soul about whether to carry on". Even with the rider that Blair was now "in steely mood" and had dismissed reports of a promise to hand over to Brown about now as "absolute rubbish", the suggestion that the Prime Minister had agonised about carrying on was startling.

I don't believe it. Before I get an angry phone call from the BBC, I had better say that I am sure that Blair has "told friends" that he had been "seriously reviewing his position". But I think this is a pose. Partly, it is because he wants to minimise perceptions of himself as arrogant, and deter comparisons with Thatcher, and her desire to go "on and on". As important, though, is that it is part of his Gordon Brown Ego Management Programme, one of the underrated drivers of prime ministerial strategy.

One of the reasons why speculation about Blair's future has run so corrosively over the past three months is that Blair himself has been reluctant to squash it with categorical statements of his intention to serve a full parliamentary term if he wins the next election. This is not because he harbours a secret plan to quit but because he wants to allow his next-door neighbour to keep the flame of hope alive.

It is a difficult balancing act, and it has clearlyunnerved several of Blair's most important supporters. (The other thing that might have unnerved them was Peter Mandelson's support for Brown as Blair's "natural successor" in his curious interview with Alastair Campbell last week - but I suspect that had more to do with Mandelson's desire to avoid Brown blocking his appointment as European commissioner.)

What is significant is that none of the speculation about Blair's future is being stoked by Her Majesty's Brown Camp, as the Treasury has been renamed. Despite the howl of rage two weeks ago from the Chancellor's spokesman, complaining that a book written by the Prime Minister's former economic adviser was "orchestrated to put the Treasury in a bad light", the ceasefire has held.

The reason is that Gordon Brown understands the four facts as well as anyone else. He knows that Blair is not going to stand down voluntarily if it looks like capitulation to pressure or an admission of failure. He wants to keep his attack dogs down and be supportive in public in order to give Blair the space to decide that he can hand on the baton with honour.

That is why those ministers who are jittery because July is the "last chance" to organise a handover to Brown before the next election seem to have misread the situation.

It is worth recalling the Labour Party rules on the leadership, which are near the front of many minds at Westminster. It would take about four weeks to hold a leadership election, and there is no question of the party deciding, as the Conservatives did, that the procedure could be skipped and Brown installed by acclaim. So Blair would have to announce his intention to resign, then hand over power once a successor had been elected. I do not believe that is going to happen for a few years, but the Brown camp have one scenario that is not demonstrably implausible. I call it the Bob Hawke Scenario. Hawke replaced the uncharismatic Bill Hayden as leader of the Australian Labor Party on the day Malcolm Fraser, the Liberal Prime Minister, called a general election in 1983. Four weeks later, Hawke won the election and went on to win three more. There is something to be said for changing leader just before an election. Indeed, Patricia Hewitt and Charles Clarke, two of Blair's worried supporters, admitted afterwards that the Labour Party might have won in 1992 if it had dumped Neil Kinnock - for whom they were working - in favour of John Smith before the campaign.

It is conceivable, therefore, if the press has shut up about the rights and wrongs of the war by then, and the elections in Iraq go ahead reasonably peacefully in January next year, that Blair could judge that his work has been done. He would have achieved a form of closure in Iraq and put the policies in place for public service reform at home.

Conceivable, even though it is not going to happen. But it is important for Blair that his next-door neighbour has that glimmer of hope to keep him on side. Politics is a cruel and deceptive game.