Alan Watkins: Things must be bad. Everyone's cheering

Political journalists are, by and large, men of peace, even in their domestic lives. So it is surprising – or perhaps it is not surprising at all – that so many of their figures of speech derive either from the battlefield or from the boxing ring. There were several commentators who noted after Prime Minister's Questions on Wednesday that, while Mr Gordon Brown had endured a terrible week, Mr David Cameron had been unable to deliver the killer punch or the knock-out blow.

It seemed to me that these observers were asking rather a lot of Mr Cameron. He did not have to do very much. The facts spoke for themselves. What he had to do, he did. And Mr Brown began by making an apology which in former times, would have been called "manly".

What spoilt the occasion, from the Prime Minister's point of view, was that an exhibition of contrition had been turned by the Labour backbenchers into an attempted triumph. "More, more," they bellowed. The practice became common, I think, in the last few years of Mr Tony Blair's premiership. The Whips were making the best of a bad job. It did not work then with Mr Blair, and it does not work now with Mr Brown. Nor does the constant waving of order papers fool anybody.

To be fair to Mr Brown, and Mr Alistair Darling, as well, they have both behaved with a certain amount of dignity. But the prospect of losing their seats makes the government backbenchers distinctly jumpy. They are accordingly putting on a show of loyalty to Mr Brown. Dignity does not enter into the matter. As the early 19th-century prime minister George Canning put it, their principal function is "to cheer the minister".

They are cheering the minister precisely because things are so bad. So much is agreed. The difference is between those who think the Government can make a recovery and those who think it is sunk – that it has, in the favourite phrase of the week, reached a "tipping point".

There is no political law of tipping points. In 1961, Harold Macmillan's government began to decline; in 1963, he resigned a few months after the Profumo affair; most people thought Harold Wilson would win convincingly; but Macmillan's successor, Alec Douglas-Home, ran Wilson close.

In 1967, devaluation was a tipping point, but people did not spot it at the time. They thought Wilson would win again, as Labour was, in Wilson's own phrase, "the natural party of government". Nor did Edward Heath have a tipping point, whether with the hiking of the oil price in 1973 or the three-day week later on. As the great batsman Denis Compton, remarked at the time: "I'm not working an extra day for anybody." Heath was, however, generally expected to win because of the unpopularity of the trade unions.

It is probably true to say that the Falklands War was the tipping point for Margaret Thatcher. It was so recognised at the time. Even so, speculation continued right up to the 1983 election that the new Liberal-SDP alliance might hold the balance in a parliament where no party had an absolute majority.

The tipping point about which everyone is agreed is our forced exit from the exchange rate mechanism of the European Monetary System in September 1992. Our entry had been urged by John Major and Douglas Hurd; supported, at first reluctantly, then enthusiastically, by Mrs Thatcher. John Smith, the Labour leader, and the young Gordon Brown, gave the project their warmest wishes. After the débâcle, Norman Lamont survived for a further eight months before being succeeded by Kenneth Clarke. One aspect to his departure was that he was allowed to make a resignation speech, as others likewise have been allowed to do in recent times. In fact these departing ministers have not resigned but been given the heave-ho by the prime minister.

In his speech, he said that the Major government, was "in office but not in power". This was widely reported at the time and hailed as an original remark. I have nothing against Lord Lamont – I am quite fond of him – but the phrase was first used by a Labour figure about Ramsay MacDonald's minority government in 1924.

Mr Clarke then proceeded to prepare the way for Mr Brown's tenure of the Treasury after 1997. Perhaps Mr Brown has stepped away from the paths of virtue as trodden by Mr Clarke. Hospitals are being driven into bankruptcy by the private finance initiative; London Underground has met with a similar fate, for the same reason; Northern Rock crashed to the ground under a financial regime encouraged by Mr Brown.

This was not Mr Clarke's fault. Indeed, Mr Clarke, taking one year with another, as the Chancellor of the Exchequer used to do in olden times, was quite good at his job. Our departure from the ERM inaugurated the good times. Lord Lamont might have performed just as competently as Mr Clarke if he had been allowed to carry on in May 1993.

The myth of Tory economic competence may have been destroyed – everybody says it was – but the evidence is not there. The evidence is, rather, that people became fed up with the Tories, for a variety of reasons. One was that Mrs Thatcher had been jettisoned brutally. Another was that Mr (as he then was) Major became entangled with his "Back to Basics" slogan, which had nothing whatever to do with sexual morality, though the newspapers said it had. Then again, the Conservative Party put its divisions on display in the House week after week. So one could go on.

A commentator wrote last week that, if it went on in this way, Mr Brown's government would be unable to carry on till June 2010 (for some reason I have now forgotten, it is a month after the five-year limit). The administration would, so the writer thought, "implode". I have my doubts. The spectacle would not be pretty or edifying but, with a majority of over 60, the Government could continue. If Mr Brown were so foolish as to force a vote on detention without trial of over 28 days, he might well lose it. This makes last week's intervention by the former Attorney General and the Director of Public Prosecutions all the more significant. Mr Brown could lose the vote and much of his authority, and accept his defeat. It was what the Major government did in 1993 after a defeat on the Social Chapter of the Maastricht Treaty.

A perfunctory threat to have an election was held over the heads of recalcitrant MPs by the Downing Street of its day. A cabinet colleague of Mr Major's remarked: "We wouldn't have let him get half-way down the Mall." The threat to hold an election is an old one.

Wilson used it once or twice in the late 1960s. It is empty, because by threatening recalcitrant members he would at the same time be imperilling his own position as Prime Minister. It is not, I suspect, a threat we shall be hearing from Mr Brown. He will have to keep quiet for a long time.