BRITISH Prime Minister Gordon Brown's aides believe he needs to endure only one more week of torture over his leadership before the Labour party and the media realise he is staying until the election, and he can then start to be judged fairly alongside David Cameron, leader of the opposition Conservative party. But Brown also knows the next few days could be the most perilous for his premiership since he took office in May 2007.

He needs to seize the initiative quickly by resolving sharp differences of view within the cabinet on a full programme of constitutional reform. He needs to navigate a fraught reshuffle, probably on Friday, that could see changes to the chancellorship (finance minister) and the Home Office (interior ministry), two of three great offices of state.

And he will have to manage a tense party as it goes through a drawn-out 72 hours of escalating panic in the face of crushing reverses in the county council elections on Thursday night and throughout Friday. That panic will reach a crescendo on Sunday night as the European election results trickle through, and Labour faces the prospect of coming fourth behind not just the Conservatives and the Liberal Democrats, but even the UK Independence party (Ukip).

As one minister said on Monday “The actual level of the Labour vote will make a massive categorical difference. It depends if it is 15 per cent, 25 per cent and 35 per cent. The actual level makes a world of difference to Gordon and the party's mood.”

All the while, Brown will have to show a steadier hand in response to the daily drip of allegations about politicians' expenses coming out of the Daily Telegraph. He will not want a repeat of Tuesday, when the chancellor (finance minister), Alistair Darling, and Brown both put out statements insisting the Telegraph's latest allegations were wrong, only for the denial to be retracted within two hours.

But the prime minister reckons if he can chart these perilous waters intact, he will be in the clear and can set out what he describes as a national plan for Britain.

Plans are still being discussed for a citizens' summit, a constitutional convention, a panel of outside experts who would look at electoral reform, a bill of rights, and a written constitution.

Brown can probably resolve the differences in the cabinet over constitutional reform, even if there is frustration at the slowness of the government reaction. The greater problem is the imminent reshuffle. But as one cabinet aide admitted “Normally reshuffles are displays of prime ministerial power and patronage, but this could be the opposite. Some ministers could walk out or resign, and then the whole thing unravels.”

The betting inside cabinet circles is that the reshuffle will take place on Friday or Saturday between the close of polls and the European election rout. Brown at that point will be on the brink of a disaster, but its full scale will not be known, thus destabilising any cabinet members thinking of mounting a coup.

Similarly, those on the backbenches wanting to oust Brown — the most likely course of events — will probably have to raise the standard of rebellion after the polls close on Thursday night, but will not know if the voters have provided them with the ammunition they need. The rebels will have to build momentum over the coming weekend — and all in the face of a display of “prime ministerial power” over his cabinet colleagues.

But that depends on the reshuffle going smoothly.

Some changes will be easy enough. Jacqui Smith, the home secretary, looks politically broken and no longer has the stomach to stay in the cabinet after her husband took the hit for the purchase of pornographic videos on expenses. She is probably reconciled to losing her marginal seat. Similarly, Geoff Hoon, the transport secretary, may fear he is expendable.

But axing Hazel Blears, the feisty communities secretary, would be more difficult. She feels aggrieved that she was singled out by Brown for behaving unacceptably over the designation of her second homes when she felt other cabinet ministers had acted similarly. If sacked, she could be a difficult backbench voice.

Even more, Brown is in a dilemma over Darling. He has been a loyal ally for a generation, and taken many hits on behalf of Brown over the last year. But there is dissatisfaction inside the prime minister's office at No 10 Downing Street at the way in which Darling fails to attack the Tories convincingly on the economy.

— The Guardian, London