As Downing Street erupted in conflagration on Friday afternoon a giant mechanical beast three storeys high came lumbering through the smoke. It staggered across Horse Guards Parade to Trafalgar Square like a dazed creature from another world. Its driver lacked all direction and seemed oblivious to the chaos he was causing. Policemen rushed here and there. Only one thing was for sure. The beast was not what it purported to be, an elephant. It was called an “experience”.

In place of government Britain now has the Tony Blair experience. There is a man and a miasma of questions, moods and tenses.

When will Blair go? When should Blair go? In whose interest is it that Blair goes, and whose that he stays? The reshuffle was, like all the prime minister’s decisions, reactive, abrupt, incoherent and discussed with nobody. It was the surest possible sign that he has no intention of resigning. To connoisseurs of these vintages, it had the ruthless bouquet of a Chateau Macmillan ’62 and the bitter aftertaste of a Thatcher ’89.

Following a terrible fortnight, Blair displayed the one muscle a prime minister always keeps in working order, that of patronage. The loyalist Tessa Jowell could be heard amid the noise uttering the Blairite battle cry, “The headlines, the headlines”.

The tossing of Charles Clarke’s corpse to the press was hardly a symbol of Blair’s strength, nor was his replacement by the all-purpose pit bull, John Reid, in his eighth job. The humiliation of Jack Straw, Geoff Hoon and Ruth Kelly, and the upheaval of virtually every department was not refreshment but panic fidget. It inevitably set the Westminster hyenas howling about Downing Street’s incapacity and waning authority, as if abstract nouns could hound a man from office.

Whatever new deal Blair may have reached yesterday with Gordon Brown, he has no reason in his own mind to resign. Whatever “letter” may be circulating among backbenchers, they have never had the stomach for a showdown with Blair, any more than has Brown. Blair’s only Commons difficulty is his habit of taunting it with rotten legislation. A no-confidence vote is inconceivable.

The country is not enduring economic crisis. The prime minister was elected only last year and has said he means to serve a full term. Since he will not fight the next election he has no fear of personal rejection. Nor do last week’s local election results spell inevitable doom for Labour — a prospect that finally did for Margaret Thatcher. They are par for the course for a government in mid-term and there are many precedents for recovery, including under Blair.

The theory that Blair will thus awaken one morning and suddenly decide to sack himself is bizarre. It was to meet just this situation that he laboriously rewrote the Labour constitution back in the mid-1990s. He made the leader’s position immune to visits from men in cloth caps or grey suits, from national executive committee edicts and conference resolutions. The party became presidential. Under the rules, engineering Blair’s involuntary ejection would require a conspiracy and a palace coup.

Blair was shrewd enough to know what such conspiracies were like. He saw them make life hell for Margaret Thatcher, Neil Kinnock and John Major. In this always lethal leadership endgame Blair is strengthened by having just one threat and having it well within his sights.

Brown would have to be at the centre of any leadership coup since he must give the nod to an early leadership challenge of which he can be the only beneficiary. Besides, there is a critical mass of Labour Micawberites who, while appalled at the state of the party, are unattracted to a Brown leadership and would prefer to wait a couple of years to see what turns up.

The Blair-cannot-last thesis assumes a constitutional deus ex machina that Labour no longer possesses. The prime minister is fit and shows no lack of self-belief. His on-off cruelty to Clarke and his obeisance to the media indicate no new deference to reality and a constant readiness to spin every passing incident to his advantage. Like all long-serving leaders he has boxes to tick, dates in his diary, records to beat. He is not cracking under pressure and gives no sign of reneging on his declared bargain with the electorate and history, that he would leave at the end, not the start, of his third term.

Brown’s supporters can wail all they like. They clearly feel their man’s time has come and that he needs three years to stop the rot and prevent David Cameron’s Tory advance.

To this, Blair’s supporters argue that Brown is not necessarily an electoral asset against Cameron. Short rather than long sprints to a first election have always suited incoming prime ministers, notably Eden (one month), Macmillan (two years) and Major (two years). Few new leaders seem to improve by long exposure to the glare of Downing Street before facing the voters, as Callaghan found in 1979.

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