A destructive proposal, but Lord Heseltine is doing his party a service

Michael Heseltine is to be congratulated on cutting through the self-imposed restraints which prevent Conservatives honestly appraising their plight. In his interview with The Independent today, he cruelly but rightly says that the party, flatlining at 30 per cent in the opinion polls for a decade now, needs to be at "48 to 50 per cent to have a ghost of a chance of winning the next election".

And, in laying the blame firmly with Iain Duncan Smith, he bluntly contradicts the consensus that one member, one vote is the best way for political parties to choose their leaders.

In this he exposes the under-remarked paradox of last year's Tory leadership election, which is that, had the decision been left to MPs, which had been the system since 1965, they might have made a different choice from that made by the party membership. Lord Heseltine asserts bluntly that Tory MPs would have chosen his pro-euro ally Kenneth Clarke; but this is not necessarily so. It is true that Mr Clarke came top of the last three. But if the final run-off had been entrusted to MPs, Mr Duncan Smith would probably still have won, because more of Michael Portillo's supporters were right-wing anti-Europeans than not.

Where Lord Heseltine scores, however, is his observation that an election held now almost certainly would produce different results depending on the franchise. Tory MPs would turn to Mr Clarke, out of desperation more than conviction, whereas most party members would never vote for such a jovially unrepentant Europhile.

The principle of one member, one vote remains the surest and most democratic foundation for party leadership, but it has always contained a potential contradiction. A leader needs to command the confidence of the majority of his party's MPs in the House of Commons; yet it is possible for a leader to lose that confidence, as Mr Duncan Smith is close to doing now, while remaining the preferred candidate of the wider membership. As Lord Heseltine rightly but rudely points out, Tory members in the country are extreme, inward-looking and very, very old.

This does not mean that the Tories or any other party should go back to having their MPs elect their leader; it is more a measure of the depth of the hole in which the Conservative Party remains trapped. A putsch by the parliamentary party to install Mr Clarke as leader might improve their standing a little, not least by reminding voters that they still exist, but it would solve few of the party's underlying problems and make some of them much worse.

Yes, Mr Clarke would make a better fist of opposing the Government. In the past few days, to take a random example, Labour has offered a series of U-turns, missed targets and splits. Mr Clarke would have exploited the rifts between Tony Blair and his Chancellor over top-up fees and market mechanisms in public services. He would have made more of Gordon Brown's downgraded economic forecasts, and would even have done a better job of questioning the Blairs' joint judgement of friends and property dealings while pretending to stay out of their private life.

But switching to Mr Clarke would not solve the deeper crisis in the Tory party. It cannot decide if it is liberal or authoritarian; or how to do a better job than Labour of reforming public services. For all the attempts at modernisation by Mr Hague and Mr Duncan Smith, including one member, one vote ballots for leader, the Tory party remains unwilling to face up to the scale of the change required of it.