Beware, Mr Blair, of theThatcher effect

It used to be written in the textbooks that a Prime Minister who was sound in mind and body and had an adequate majority was impregnable. Students absorbed the message, obediently reproducing it in their examinations. Something over 11 years ago, it was proved wrong. A Prime Minister who was in good health, possessed a majority of nearly a hundred and had, moreover, won three general elections on the trot was turfed out, to general surprise. I refer, of course, to Margaret Thatcher.

But perhaps her fall proved the old maxim only partly wrong. For though she was then in good physical health, there were doubts not so much about her sanity exactly as rather – how can one put this? – about her mental balance. This was certainly a factor in the refusal of the Cabinet to support her in the second ballot in which she was proposing to offer herself for election. She might not have been chucking inkpots around No 10, as Anthony Eden had been doing during the Suez crisis. But there was no doubt nevertheless that she had been behaving in a most peculiar manner, what with one thing and another.

Mr Tony Blair has an even larger majority than Lady Thatcher. He has won two elections. As a younger politician, he is in even better health than she was. But almost exactly the same doubts are being expressed about his own state of mind. They are being expressed in the Government as much as in the Commons tea room, though naturally the consumers of the most intractable rock cakes known to man can afford to be less inhibited.

Does Blair know what he is doing? Is he about to drag us into dangerous and perhaps limitless wars at George Bush's coat-tails, in Afghanistan, possibly in Iraq as well? Harold Wilson, for all his faults, refused Lyndon Johnson's request to provide even a token presence in Vietnam. Why, Blair – as he is usually called, unlike his predecessors Jim, Harold and Clem – has provided not just a token presence but a whole bloody army, or a good part of one.

Whether this talk leads to anything remains to be seen. Probably it will not. But the policy of this column is to emulate the Boy Scouts and to be prepared. Margaret Thatcher was brought down partly by her backbenchers, by Michael Heseltine and by her Cabinet. But she was brought down mainly by procedure. Few of her supporters took the trouble to understand it, even if they were capable of so doing. Certainly her campaign manager in the first ballot, Peter Morrison, went under the impression that the 15 per cent "surcharge" on the majority in the first ballot (which she failed to obtain by four) was the same thing as 15 votes.

There is no comparable level of ignorance in the People's Party. Even so, there is a certain lack of knowledge of the means whereby a Labour Prime Minister may be disposed of. This is understandable enough. In the old party constitution, the matter was passed over. Of Labour's Prime Ministers, Ramsay MacDonald excluded himself, C R Attlee lost an election, Wilson resigned voluntarily and James Callaghan lost a vote of confidence. The party's new rules lay down: "When the PLP is in government and the leader and/or deputy leader are Prime Minister and/or in Cabinet, an election shall proceed only if requested by a majority of party conference on a card vote."

In olden times it was assumed that if a Labour Prime Minister was to be deposed – unlikely though that might be – the initial push would have to come from the Cabinet. The MPs would then choose a successor by exhaustive ballot, as they had on numerous occasions when they were choosing a leader of the opposition. In 1976 Lord Callaghan was elected in this way after Wilson's resignation without any difficulty. In the same fashion, in 1990 Mr John Major succeeded Lady Thatcher.

Lord St John of Fawsley and other "constitutional experts" had made objections before these stirring events to the effect that the Queen was being deprived of her prerogative to choose her first minister. They proved unfounded. Indeed, from the evidence, Her Majesty was grateful for the removal of any need to chose.

With New Labour, we are in the position where sacking the Prime Minister is up to the party conference alone. This is now split 50:50 between trade unions and constituencies. Members of Parliament have, as such, no locus standi at this stage. They come into their own at the next stage, of nominations for the new election. If there is a vacancy, the candidate or candidates must receive the support of 12.5 per cent (or 52) of Labour MPs. If there is no vacancy but, rather, a challenge, the figure rises to 20 per cent (or 82).

It is not at all clear whether the displacement of a Labour Prime Minister by the conference counts as the creation of a vacancy or not. Nor is it clear from the rules whether Mr Blair, were he to suffer such an ungrateful fate, would have to retire from the contest or be eligible none the less to stand in the ensuing election, if he obtained the requisite level of support from his MPs. What is clear is that all the candidates must be MPs.

At the third stage, the election itself, the electoral college comes into operation, with a third share each for MPs, individual members and trade unions. It is one of the great confidence tricks of modern politics that New Labour has somehow been converted to the principle of one member, one vote. The attachment to the old ways was demonstrated in the unfortunate selections of Mr Frank Dobson to fight in London and Mr Alun Michael to do likewise in my own native land. The rules contain a further curious provision:

"When the party is in government and the party leader is Prime Minister and the party leader, for whatever reason, becomes permanently unavailable, the Cabinet shall, in consultation with the NEC, appoint one of its members to serve as party leader" – and presumably as Prime Minister – "until a ballot under these rules can be carried out."

This is straightforward enough in the sad event of Mr Blair's death or serious illness. The Cabinet and the National Executive would sit down and have a fight about the respective merits of Mr John Prescott and Mr Gordon Brown, a contest which Mr Prescott's supporters would probably win on the basis that he was the deputy leader after all.

But what if Mr Blair were displaced by the conference? Surely he should carry on as Prime Minister until a successor was chosen, as Wilson did in 1976, and Lady Thatcher in 1990. One creature that the rules dispatch is the stalking-horse, much fancied in the last few weeks. After the removal of the PM, the contest must by definition be for serious runners only.