John Curtice: Why the Cameron comeback deflated the Brown bounce

David Cameron must hardly be able to believe his good fortune. By the end of Labour's conference, the party's lead in a rolling average of the last four opinion polls had stretched from six points in mid-September to 11 points. The danger of an early election ending in crushing defeat for the Tories seemed all too real.

Now, just a week later, that same rolling average puts the Conservatives neck and neck with Labour, enough of a turnaround to ensure Mr Cameron did not have to face the voters at all.

Instead, it was Gordon Brown who feared an election. While Labour might still have secured a majority of 36 on the latest poll figures, Mr Brown could no longer be confident of a "personal mandate".

So why has the Cameron Comeback deflated the Brown Bounce?

The first reason is the Tory proposal to relieve most people of inheritance tax. More than one poll has found that it is second only to council tax in its unpopularity. One Mori poll found that over two-thirds think it unfair to tax property after death. And although only 6 per cent of estates pay the tax now, one in three people reckon they might have to in te future, a BPIX poll found yesterday.

The proposal struck home. No less than 40 per cent say that it makes them more likely to vote Tory, and only 5 per cent less so, according to an ICM poll.

The second reason for the Troy recovery is the restoration of Mr Cameron's popularity. According to YouGov, 49 per cent thought he was doing well as party leader a year ago. By August that had plummeted to 29 per cent. Now it is back up to 54 per cent. Perhaps equally importantly, 38 per cent now feel that the Conservative party has changed for the better.

Mr Cameron still trails Mr Brown on many attributes. But he has been given a second chance to convince the country of the merits of his new brand of Conservatism.

John Curtice is Professor of Politics, Strathclyde University