The combination of poor local election results and a curious and clumsy reshuffle has left Tony Blair on the ropes. The air is thick with talk of “plots” and “coups”, poisoned letters and even a stalking horse challenge to the Prime Minister at the Labour Party Conference. This will be an especially mischievous week at Westminster. If handled wrongly, it would leave the impression of a Government that has lost the will to govern. That would be a bizarre spectacle a mere year after a general election.

This is hardly a state of affairs that should suit Gordon Brown, Mr Blair’s near certain successor, never mind the Prime Minister. It has to be said that Mr Blair is not always best served by the Blairites. There is a sense of paranoia about Mr Brown that better reflects the career anxieties of certain ministers and advisers than the solid facts of the matter. The idea that the recent troubles are due to a sophisticated Brownite conspiracy is fantastic. The Chancellor did not arrange for the Deputy Prime Minster to have an affair with his diary secretary, the Home Secretary to release, accidentally, foreign national prisoners without proper deportation proceedings, or bribe nurses to heckle the Health Secretary.

Despite this, there are obviously Labour MPs who are perfectly willing to act in the Chancellor’s name. Those pressing for the Prime Minister to resign with excessive haste are essentially a coalition of the ideologically defunct and the personally disabused. This mixture of hard Left and hard cheese seeks to present itself as the mainstream of the Parliamentary Labour Party. In truth, it is an embittered faction hostile to everything that new Labour has ever stood for, and the best news that the Conservatives have had in years.

Precisely because of this, the Chancellor should be wary of his would-be champions. Their objective is less to praise the incoming Caesar than bury him under a commitment to retreat from the new Labour agenda. If that were to occur, then Mr Brown might win the crown but it would not fit on his head for a lengthy period. He would be obliged to appoint a Cabinet that would not be wholly to his taste, to shelve reforms that, if anything, are too meek , not too radical, and to move into exactly the territory that David Cameron would hope he takes.

The Chancellor must avoid this trap. The coming days will provide a severe test of his temperament. The cosy route for him would be to be invisible, neither encouraging a revolt nor distancing himself from it. Such evasiveness would leave the Prime Minister exposed and fundamentally undermine a reform programme that Mr Brown has helped to implement, though sometimes with less than the requisite enthusiasm. He would inherit a party that had lost its leader and its way, as internecine ideological battles would inevitably follow the fall.

There are also, though, obligations on Mr Blair . He is right to resist publicly naming a date for his departure, an act which would drain him and the Government of authority. But he and Mr Brown must reach an accommodation, for their own sake and, most importantly, for that of the country. The Government and the Labour Party need a period of calm — the letter writers should put away their pens, the plotters should sheathe their daggers, and a reforming Government should get on with the business of reform.