Alan Watkins: Robin Cook must deploy his depth charge

At some time in the early 1950s a friend of mine entered a chemist's shop in Ammanford, Carmarthenshire, and asked for a "depth charge". The shop assistant summoned the manager and, after some whispered consultation, a packet of Durex contraceptives was pushed furtively across the counter.

"Thank you very much," the young man said. "Very handy these will come in I have no doubt. But what I was really looking for, to be perfectly honest with you, was some Alka-Seltzer."

Mr Robin Cook finds himself in the reverse position. What the House of Commons needs is a depth charge and he has provided some Alka-Seltzer instead. Yet in some ways he is the most interesting member of the Government.

He did not get off to a good start as Foreign Secretary, when Mr Alastair Campbell effectively forced him into regularising his matrimonial arrangements with all the ferocity of a Victorian paterfamilias. He was stuck with his "ethical" foreign policy when no one knew what it really meant: a scrupulous regard for international law in all circumstances – or that, in the interests of a higher morality, the United Kingdom was prepared to override international law and intervene in the affairs of other states? We know now that Mr Tony Blair believes in the latter. But Mr Cook did little to clear it up.

Though he had done three years as foreign affairs spokesman before taking up a position in a real government, that was not, one felt, where his interests lay. It was certainly not where he had made his reputation. Throughout the 1980s and 1990s he was Labour's most effective parliamentary performer, rivalled only by John Smith. The arms-to-Iraq affair, which saw Mr Cook's greatest triumph, was less a matter of foreign policy than of domestic politics.

In office Mr Blair retained him for four years. It was rumoured, even before the formation of the new administration, that he would soon be for the heave-ho. I did not believe it. Though Mr Cook has never been popular with his leaders – from Mr Neil Kinnock onwards, he has hardly bothered to conceal his conviction that he is cleverer – he has also been feared by them.

He is even feared, a little, by Mr Blair, rather as Mr Blair fears Mr Michael Howard. Despite, perhaps because of, his televisual charm, the Prime Minister is apprehensive of genuine debating skills. With Mr Cook, there is another reason for alarm. He is seen as the only plausible leader of the Left. Or, at any rate, he used to be seen in this way. It may be that Mr Cook's spell at the Foreign Office has taken the sheen off the coat. He is among those ministers – Mr John Prescott and Mr Jack Straw are others – who have, in the language of the racing correspondents, failed to train on.

Even so, I was not surprised when Mr Blair made him Leader of the House. Most of my colleagues saw this as a demotion, a humiliation even. I did not view it in quite this light. Admittedly the job was no longer a step on the ladder to No 10, as it had been till the 1940s. Later, ambitious politicians regretted the absence of a department with lots of officials about the place. But you could still make changes which affected the way we were governed.

The two most successful reforming Leaders of recent years were R H S Crossman and Norman St John-Stevas. Both were intellectuals in politics; neither was a "House of Commons man". Crossman inaugurated morning sittings and extended the committee system, less from any desire to keep the government under greater surveillance than from an acknowledgement of the proverb that Satan makes work for idle hands; Harold Wilson then had a majority of 99. Lord St John, as he now is, pushed Crossman's reforms further, setting up committees to cover the principal ministries.

In 1981 he was sacked in Margaret Thatcher's massacre of the Wets. Subsequently he blamed me. He said that my reproduction of his nicknames for her, "the blessed Margaret" and "the Leaderene", had been the cause of his downfall. Feeling guilty about the charge, I sought the advice of a former minister.

"I shouldn't lose any sleep about it," he advised. "She never reads the papers anyway, and she certainly wouldn't read anything by you."

Both Lord St John and Crossman regarded themselves as being at a distance from the government, representing the House in the Cabinet: much as the old Ministry of Labour saw itself as representing the trade unions, or the old Ministry of Agriculture the farmers. When Sir Bernard Ingham described another former Leader, John Biffen, as a "semi-detached" member of the government he was describing no more than any Leader's proper constitutional position. Other recent Leaders, notably Mrs Ann Taylor and Mrs Margaret Beckett, have seen themselves more as adjutants to the Chief Whip, concerned with the prompt dispatch of government business and with little else. Mr Cook gives every impression of being more a Crossman, a St John or a Biffen. True, his proposals are modest. The only one of real importance is that the composition of committees should be removed from the Whips. The proposal that Prime Minister's Questions should take place at midday instead of at three suits my own habits admirably. The proposal that the House should return in early September and then adjourn for the party conferences is, however, ludicrous. Why should the conferences not be shifted back a month, so that they take place in late August and early September? This would not suit my own habits nearly so well – would not suit them at all, in fact – but there is no reason for Mr Cook to pay any regard to my convenience.

We now come to the depth charge which is not there. This is that governments should learn to accept defeats: just as Mr David Blunkett accepted, with a typical lack of grace, his defeat by the Lords over what amounted to an extension of the law of blasphemy. The Government is no longer in a position to complain about the use of the Lords' powers. The hereditary element has now been largely eliminated. The 92 peers who remain are there with the full consent of the Government. And there is no proposal to reduce the present powers of the Upper House, either now or in its fully reformed version, if that ever comes about.

Similarly, the backbenchers should use their powers. It is not up to Mr Cook but up to them, though he can help them on their way. I began this column with a reference to contraceptives. Long ago, in the advice columns which I used to read avidly, Evelyn Home and her like would counsel: the best contraceptive is No. Exactly the same advice applies today to the backbenchers who are threatened by the Whips.