Andrew Grice: The Week in Politics

How can governments survive a recession? Ask John Major

David Owen announced the party was over after his SDP finished behind Screaming Lord Sutch, the Monster Raving Loony Party candidate, in the 1990 Bootle by-election. He disbanded the SDP a week later.

After Labour's humiliating fifth place behind the BNP in Thursday's Henley by-election, some cabinet ministers are saying the next general election is already over; that the best Labour can do is to minimise its losses so it is only out of office for five years. "All we can do now is try to have a managed exit from power," one told me.

Such talk angers Labour backbenchers who want to force Gordon Brown out of office before the election. They say that if the ministers believe that Mr Brown will lose the election, they have a duty to play the last card that might save it.

The Cabinet does possess the power to push Mr Brown out; he could not survive a "go now" request by senior figures such as Jack Straw, Geoff Hoon and Alan Johnson. But cabinet ministers show little sign of wielding the knife – for now, at least.

They say there is no guarantee that a David Miliband or Alan Johnson premiership would revive Labour's fortunes. They fear the blood on the carpet could make things even worse. There might well be a divisive leadership contest rather than another coronation. "We made our bed a year ago by choosing Gordon; now we must lie on it," said another cabinet member.

Yet the phone lines between cabinet members will probably be buzzing this weekend, thanks to Henley. Some say they may yet move against Mr Brown if he shows no sign of turning things round by the autumn.

The by-election made the headlines about Mr Brown's first anniversary in Downing Street yesterday even worse. The danger is that they yet again eclipse the Brown message, so the power normally at a government's disposal is worthless. To be fair, there have been some recent signs of the Brown government cutting its cloth to a few key themes, instead of the usual blizzard of initiatives, micro-managed by the Prime Minister himself.

Monday's launch of a new blueprint for the NHS to mark its 60th birthday is an important moment in the fightback plan. Some cabinet ministers insist Mr Brown can still turn it round and say the NHS anniversary gives a clue how. They say voters are still closest to Labour's core values, epitomised by the NHS, of opportunity for all and a fair society. They think David Cameron has not yet convinced the public his new model Tory party really believes in such values, even if he espouses them.

The tragedy of Gordon Brown is that he was best-placed to embody those traditional Labour values but the 10p tax fiasco – his own making – has tarnished his credentials. The other mystery, which I cannot solve, is how he seemed so unprepared for being Prime Minister after watching Tony Blair up close for so long. Remarkably, he didn't seem to realise that in No 10 you have to juggle five crises a day rather than five a year at No 11.

The 10p tax disaster was just one of several examples of Mr Brown's strengths turning into weaknesses. The Iron Chancellor became a dithering Prime Minister over the election that never was. For me though, the turning point was his ill-advised visit to Iraq during the Tory conference. That turned a spin-free antidote to Mr Blair into just another tacky politician. In the Tories' press room in Blackpool, journalists cheered when John Major popped up on the BBC to attack Mr Brown's opportunistic visit. It was a pivotal moment.

The most important strength-to-weakness shift is on the economy. Even Mr Brown's critics acknowledged his good record at the Treasury. Yet, in the public's mind, it has turned to dust. It may be unfair to blame him for problems caused by the global credit crunch. But that's politics, and he wasn't slow to claim the credit when the world economy was doing nicely while he was chancellor.

Brown allies insist he can still go from weakness back to strength on the economy. If Britain survives the storm, they hope, he will win a grudging respect. Then Labour's values could yet win the party a fourth term.

I am not so sure. When a young puppy called David Cameron worked at Tory HQ before the 1992 election, he and his fellow staffers were ordered to insert "world" in front of "recession" in every ministerial speech and statement in the hope the Tory government would escape the blame. It worked, having an impact in the opinion polls, and John Major won the election.

Mr Cameron is convinced that blaming global problems won't work for Mr Brown: unlike Mr Major in 1992, he has been on the scene a long time and voters have now made up their minds about him.