John Rentoul: They'll need a lot more than frilly knickers when Gordon's in charge

What the Conservative Party needs is better frilly knickers. So says Alan Duncan, the latest candidate to join the leadership contest. Any good political strategist will say that the element of surprise is essential to success, but perhaps that is not what is needed. What Duncan said was: "Marks & Spencer was a fantastic brand in good times, but if you have a lousy chief executive officer and lousy knickers you don't do well. Like M&S we need both a good CEO and better frilly knickers."

This tells us more than Duncan could possibly imagine about the state of British politics. David Davis is almost certain to win the Conservative leadership, but he has already missed an important opportunity. These are priceless moments, when journalists are actually interested in the Conservative Party. And what has the front-runner come up with? He has spoken in the House of Commons once since the election, in the debate on the Queen's Speech. He was good, but not memorable. He wrote an article for The Sunday Telegraph last weekend, which was good, but not memorable. But then, what have the other contenders said? Nothing anyone can remember. As Sir Peter Tapsell, possibly the last remaining knight of the shires (in his case Lincolnshire), said to the 1922 committee of Tory backbenchers last week in his best Churchillian tones: "We are effectively leaderless." So what fills this vacuum? Alan Duncan's frilly knickers.

David Davis seems to believe that the best strategy for the front-runner is to sit tight, which must be to misread the importance of momentum. If you have got it, you should use it. Should he not have given a big speech saying something unexpected by now, or done something that confounded the image of the Tory party as hard-faced, backward-looking and out of touch? I am not saying that he should spend a day as a hospital porter or change places with a lone parent - after all, Davis was brought up by a single mother himself - but Michael Portillo was on to something with those stunts.

Davis did a little pre-positioning before the election, taking an unexpectedly liberal line against control orders and identity cards. But by most of the electorate he is still known only, if at all, for a broken nose and a whiff of populist authoritarianism, while his party remains hobbled by the negative associations of its past.

While the likely winner sits and waits, the early phase of the leadership contest provides a mildly diverting entertainment, like watching woodlice scramble in all directions when a large stone is lifted. David Willetts, the shadow Trade and Industry secretary, made the best speech so far of any of the contenders 10 days ago. He quoted authorities as diverse as Quintin Hogg, Bridget Jones and George W Bush, and produced some fine lines of his own. He warned the party against drifting into lazy "bring backery - the political equivalent of comfort eating". He pointed out the problems with the Thatcherite message of a smaller state when everyone expects government to solve complex and expensive social problems. But he was stronger on analysis and wit than on policy or positioning. He is essentially a brilliant commentator and policy wonk. As long as the Conservatives are too much the stupid party to consider Kenneth Clarke as their leader, there is only one serious stop-Davis candidate and that is David Cameron, the untested education spokesman. And, passive though Davis has been, Cameron, too, has missed his opportunity. I suspect that it is already too late for him to change the tempo and catch up with the favourite.

Is all this, though, to commit the sin condemned by Tony Benn of concentrating of personalities rather than issues? Alan Duncan, when he launched his leadership campaign, called on the party to debate its direction before turning to the question of who should be leader. This is fantasy, as was pointed out by one of the few Conservatives who is not a candidate for the leadership. Gary Streeter, the backbench MP for Devon South West, pointed out, in a Spectator discussion about the party's future, that "Blair's genius is that he embodies what New Labour are all about - he is the message".

This seems to me to be the key. Davis has yet to define himself as a leader, so the message remains fuzzy. A leader has to lead. One of Michael Howard's faults was that he confused discipline with leadership, brutally sacking an MP for speaking out of turn, while presenting a programme that read simply like a collection of unrelated gripes collected from public opinion research.

The most important consequence for the Conservatives is that they need to understand that Blair will not be the message they will be fighting at the next election. The message that they have to overcome will probably be Gordon Brown. That presents dangers and opportunities. The danger is that the "Iraq vote" will come back to Labour from its temporary lodgings with the Liberal Democrats, which would give Brown a large cushion.

It is the opportunities that are more interesting, however. No one should doubt that Blair is an exceptional politician, and that it will be difficult for Brown to maintain the same breadth of appeal across the centre ground. While Brown may reinforce Labour's base by winning back the liberal middle class, he may lose other parts of the New Labour coalition.

Yet there are few hints that any Tories understand this context for the next election: that it is primarily about personalities, not issues. It might be thought that the strategic imperative for the Tory party is to try to emphasise how much Brown has in common with everything about Blair that people do not like - and how much they have in common with the things about Blair that people used to like. Davis should hug Blair close, to claim his values as its own. A few Tories, such as Gary Streeter and some of the new intake of MPs, are open about their admiration for the Prime Minister, especially in foreign affairs. This is astute politics, not only because people like bipartisan reasonableness - it was one of Blair's own early trademarks - but because the Tories need to occupy Blair's centre ground and deny it to Brown.

I detect almost nothing of this in the Conservative leadership contest so far. The only MP to make the point is Nick Herbert, who replaced Howard Flight when he was sacked at the last minute as the candidate for Arundel. In the Spectator debate, he said Blair would be constrained on further reform of the health service. "We should occupy that ground and let Brown and the Labour Party be opponents of it." If one of the contenders were to say that they want to build on Blair's achievements, while Brown would undermine them, then we might sit up and take notice. As it is, the most unexpected feature of the Tory leadership campaign is Alan Duncan's frilly knickers. That says it all.