Leading Article: Why it ought to be Clarke If it's not Ken we all lose

It is fashionable, but fatuous, to use the word "presidential" to describe the premiership of Tony Blair. He is much more powerful - in his own country - than a mere US president. The White House, thanks to the separation of powers embodied in the US constitution, can see its policies sunk by a recalcitrant Congress, its executive actions declared unconstitutional by the Supreme Court and the president's cherished appointments thwarted by high-profile congressional committees. A British prime minister, by contrast, is underpinned by a legislature dominated by the party he leads. Provided he can control his party and his cabinet, he can control parliament. And if he can control parliament he can do pretty well what he likes, especially if, like Mr Blair, he has a huge and, by the historic standards of his party, docile majority.

All of which makes the question of who leads the Opposition an urgent matter for everyone. It is tempting, after the antics of the past week, to think of the Tory leadership as an internal issue, of interest only to committed Tories and political commentators. After all, that is how most Tory MPs appear to see it. Last Tuesday two-thirds of the parliamentary party showed a magnificent contempt for wider public opinion by voting against Kenneth Clarke, the candidate who was the runaway favourite of their own constituency activists. But who leads the Tory party is rather more important than that. An elective dictatorship, as Lord Hailsham described the British system, is a wonderfully effective instrument for change; but it can lead to dangerously overbearing arrogance. The poll tax and Westland are two examples from the Thatcher years. Margaret Thatcher tasted real fear over Westland in 1986. Had Neil Kinnock not faltered, she might (and she knew it) have been unseated. And that is as it should be. Effective opposition leaders discourage bad behaviour by those in office. In a political system notably short on constitutional checks and balances against the executive, the Leader of Her Majesty's Loyal Opposition is an important part of the constitution.

We happen to think that, of the available candidates for the Tory leadership, Mr Clarke would make the best Conservative prime minister. He is outward- looking, undoctrinaire on Europe, and has a traditional one-nation Tory sense of social responsibility. But that is hypothetical at present. More to the point is that he would also make easily the most effective Leader of the Opposition. Mr Clarke holds to the view, articulated by his political hero Iain MacLeod after Labour's last landslide in 1966, that "in parliament it should not only be the duty but the pleasure of an opposition to oppose". Partly, that is a matter of skill; Mr Clarke, like Mr Blair, is a lawyer and a first-rate dispatch box performer. But we also favour Mr Clarke on the basis of his record. Suppose that the worst fears about Labour's National Health Service review came to pass. Who would most credibly attack the Blair administration for reneging on its promises to restore the NHS? John Redwood, who for all his more recent repositioning wrote a Centre for Policies Studies pamphlet in the 1980s suggesting a massive expansion of the private health sector? Or William Hague, whose views on many issues, the long-term future of the NHS among them, have yet to be articulated? Or Mr Clarke, who fought, along with Nigel Lawson, a long battle to stop Mrs Thatcher giving tax breaks to those opting for private care? The surest way for an opposition leader to embarrass a prime minister is to attack him in terms that strike a chord with the silently disgruntled government backbenchers opposite. It is not credible that Mr Redwood or, in the foreseeable future, Mr Hague, could manage that feat. It is quite easy to imagine Mr Clarke doing so.

The Blair government has so far proved sure-footed and better prepared than anyone dared expect. But the going will get rough. There will be arguments within government over public spending, over Europe, over constitutional reform. And every effort will be made to cover them up by the most centralist and effective propaganda machine ever seen in British politics. It will be the job of the Leader of the Opposition to see that they don't get away with it. It is a measure of Mr Blair's achievement that opposition will not come from Labour itself. But it must come from somewhere. Good government depends on good opposition.