A stalking horse would fall at the first fence

It was a long time ago, James Callaghan was Prime Minister and I was writing a column in what we old journalists have been brought up to call Another Sunday Newspaper. At that time I attended meetings of the lobby, though without, I confess, much regularity. Some procedural skulduggery was then afoot in the People's Party. The precise details I have now forgotten, and they do not much matter. But I questioned the Prime Minister about them.

"Dear oh dear," he said (in this usage Jim anticipated Arthur Daley of Minder in the next decade). "I do hope, Alan, you're not proposing to give us another of your boring constitutional articles."

Last Sunday I wrote one of those articles to which Lord Callaghan (90 last week) had jocularly drawn attention. The subject was the method of challenge to a Labour Prime Minister under the party's new rules, as approved by the National Executive Committee last July.

In Lord Callaghan's time and beyond, the party constitution had been reticent on the subject, though it had found quite a lot to say about the election of a Labour leader of the opposition. It was impossible to tell whether this ancient silence was brought about by the unlikelihood of ever having a Labour Prime Minister at all or by the impropriety of challenging him once he had become one. Perhaps the whole subject was considered too embarrassing to go into, like sexual intercourse in an early guide to married life.

Indeed, as far as I can see, the only official reference that was made to the business occurred in January 1957, when Anthony Eden resigned as Prime Minister and was succeeded by Harold Macmillan on the say-so of the Queen. The Parliamentary Committee (the fancy name for the Shadow Cabinet) issued a statement to the effect that, in comparable circumstances, the new Prime Minister would not be chosen by Her Majesty but by the Parliamentary Labour Party by exhaustive ballot. It was the method adopted when James Callaghan succeeded Harold Wilson in 1976.

This was still the age when the leader of the party was chosen by the MPs alone. What he was called varied from period to period. Keir Hardie was Chairman of the Parliamentary Party. From Ramsay MacDonald in 1922 to Wilson in 1970 the official title was Chairman and Leader of the Parliamentary Party. In the 1970s Wilson and Callaghan were both called Leader of the Parliamentary Party. The first Leader of the Labour Party – here is a trick quiz question or, rather, answer – was Michael Foot in 1980.

Mr Foot was also the last leader to be elected by the old method, by the Labour MPs alone. For some reason it is often written erroneously that he was the first leader to be elected by the new method. The reason for the mistake is probably that in 1979-81 the MPs surrendered their powers. They did this with the acquiescence of Lord Callaghan, Mr Foot and Lord Healey, who could conceivably have made a difference but preferred to sit on his hands instead.

To succeed the old system we had, in 1981, the electoral college which produced Neil Kinnock and John Smith and then, in 1993, the new electoral college which gave us Tony Blair. Under these arrangements the MPs have only a limited part to play. They must produce the candidates from among themselves. They must nominate them. And, collectively, they have a one-third share in the electoral college, the other two shares being taken up by the constituencies and the trade unions respectively.

But when there is a Labour Prime Minister, the MPs have no right whatever to call an election, not even if they support a rival candidate with 20 per cent of their number or 83, the proportion necessary in a contested election. You cannot put up a candidate just like that for an election that has not yet been called and may never be called. Calling an election requires a card vote at the annual conference. It is what the philosophers term a necessary condition and the lawyers a condition precedent. There is nothing about that sturdy old favourite of party management, a two-thirds majority. A simple majority will suffice. Nor need any rival candidate or candidates be specified. The motion would be to hold an election; that is all.

Let us assume that Mr John Edmonds, Mr Bill Morris and other trade union leaders are approached in the coming months and told: "Listen, comrades, we think it would be a good idea to give young brother Blair a bit of a shock. So we're proposing to put up Peter Kilfoyle" – perhaps the most plausible of the so-called stalking-horse candidates – "to stand against him this autumn. Do you think you could help us?" The paladins of the block vote would surely tell the tearoom conspirators to go away and stop wasting their time, however ill-disposed they might be towards Mr Blair by this stage of the proceedings. If, however, these consumers of the hardest rock-cakes known to man – Matterhorns of the baker's craft – had managed to interest, say, Mr Gordon Brown in the exercise, the response might well be different. For Mr Brown has always kept his connections with the brothers from the branches in a good state of repair. Unlike Mr Blair, he believes the continuance of diplomatic relations is beneficial not only for the Government but for himself. The course of events, according to the rules, is then clear. If Mr Blair says "Do your worst", the rival or rivals must each assemble 83 signatures. If, on the other hand, he retires hurt, the new aspirants must each be supported by 12.5 per cent or 52. What is manifest is that the Parliamentary Labour Party cannot call an election on its own initiative.

Nor are there two independent, parallel conditions which must be satisfied and on which an election depends: a collection of Westminster signatures and a card vote by the conference. That is the fallacy behind much of the mistaken reporting of the past week. The card vote must precede the signatures. For the Parliamentary Labour Party no longer has an independent existence. That is the legacy of Lord Callaghan, of Mr Foot – and of Mr Tony Benn.

Quite why the notion of the stalking horse holds such attractions is difficult to understand. It originally meant a horse trained to conceal a hunter stalking wild fowl. By the early 17th century it had already come to mean someone acting as a decoy. Sir Anthony Meyer was a stalking horse when he challenged Margaret Thatcher in 1989. Michael Heseltine was not such a creature in 1990: it was Sir Anthony who had shown Lord Heseltine the way. It is unlikely that such an animal will emerge this year. Meanwhile I suggest a moratorium on the phrase.