Leading article: A rise in interest level does not presage a rise in popularity

Tory members have not been in tune with the views of the wider electorate for more than a decade

His speedy ascent leaves Mr Cameron exposed. Over the past few weeks, his appeal was based almost entirely on his political style. He was young, energetic and engagingly articulate. During the final phase, he must give a much clearer indication where he would take the Conservative Party if he becomes its leader. At the very least, he must answer more clearly where he stands in relation to several pivotal policy questions. Does his Euroscepticism extend to contemplating withdrawal from the European Union? If it does not, how would he work with other countries within the EU? Where would he find savings in public spending to finance tax cuts? Does he support the party's approach to immigration? What is his policy on Iraq?

So far, Mr Cameron has said his party has proclaimed too much about issues such as Europe and immigration, and he would emphasise other policy areas. Again he makes a presentational point. It does not mean he opposes policies which have lost the Conservatives the past three elections. Mr Cameron's challenge over the next six weeks is to frame answers to these questions that win the support of his party's activists, but start also to build a broader appeal. This will not be easy. Tory members have not been in tune with the views of the wider electorate for more than a decade.

What Mr Cameron cannot do with any credibility is to suggest that his views on key policy areas will be declared nearer the next general election. Obviously, detailed proposals must wait until then, but his broad position on Europe, the size of the state and various social policies should be fleshed out. Mr Cameron is not well known enough to argue that all these complex issues will be resolved in a policy review once he is safely elected as party leader.

The other contender, David Davis, faces an even tougher challenge. Having been the clear front runner until his party's conference, all he can do is hope Mr Cameron slips up. Already Mr Davis appears less self-confident. This is not surprising given what has happened to him over the past few weeks. No candidate has been so severely punished for delivering a single mediocre speech. Perhaps his grasp of policy detail will chime with the party's activists, but polls suggest members are planning to back Mr Cameron.

Quite probably, the leadership contest will continue to attract much attention until its conclusion in December. But Tories, including the two leadership candidates, should not mistake a wide interest for a surge in support. Polls suggest the Government retains a commanding lead. The parliamentary Conservative Party has shown its narrow limitations once more by dumping Ken Clarke at the earliest opportunity. Mr Clarke's popularity with voters and his attempts in this campaign to spell out the need for a credible economic policy made no impact on Tory MPs, too many of whom are still obsessed with Europe. More than half the parliamentary party voted for Mr Davis or Liam Fox, both candidates on the right. Some of these MPs will cause trouble if Mr Cameron attempts to move towards the centre ground. The Conservative Party is in the limelight, but still far from power.