The Conservatives are doing well but still not quite as well as they should, and need, to do. This is not related to the four-point drop in Tory support in the latest Populus poll for The Times (for details see www.populus.co.uk).

Far more important is the evidence that, despite the national swing in their favour, the Tories have failed to improve their ratings on issues such as the NHS and schools.

Voting intentions get most attention on websites, though some bloggers exaggerate the link between poll shifts and events, such as the Caroline Spelman and Ray Lewis affairs, which have probably not even registered with most voters.

It is not surprising that the freefall in Labour's rating and the steady rise in support for the Tories has halted. These movements could not continue forever; nor did they in the mid-1990s when the parties were in opposite positions to now. But the underlying trends matter: the Tories are well established above 40 per cent and Labour below 30 per cent.

The clue to decoding most polls is through the findings about public attitudes. These results are unremittingly bad for Gordon Brown, and good for David Cameron. He has decontaminated the Conservative brand, opening the way for its recent successes.

On questions of policy the message is more ambiguous. Labour's rating as the best party on key issues has fallen sharply over the past year. But it has not been symmetrical. With a few exceptions, there has not been a comparable improvement in the Tory rating.

Populus points out that there has been an 11.5 per cent swing from Labour to the Tories since last September. But only on managing the economy, tax and Europe, have the Tories done as well relative to Labour as they have on voting intentions. The shift on managing the economy was much larger, at 36 per cent.

But in several other areas, the Tories have underperformed their strong voting intentions, especially on public services. For instance, on the NHS, the number rating the Tories as the best party was 28 per cent last September, 29 per cent in December and is now 31 per cent (level-pegging with Labour). On improving standards in schools, the figures are 31, 32 and 32 per cent (now one point ahead of Labour).

There are three implications: first, the current public mood is as much anti-Labour and anti-Brown as it is enthusiastically in favour of Tory policies; secondly, the Tories still have a long way to go to establish a clear identity on policy in voters' minds; and thirdly, “it's the economy, stupid” — for all the recent emphasis on social and moral issues, what is damaging Labour and helping the Tories is the state of the economy. That will remain the key to the election.

Establishing credibility on the economy, taxation and public spending remains the most important task for the Tories, as George Osborne recognises. Any doubters should read Norman Fowler's revealing new book, A Political Suicide: The Conservatives' Voyage into the Wilderness.

This is mainly about the Tories' self-destruction in the 1990s, but, as Lord Fowler argues in his conclusion, there are clear parallels with the Brown Government's troubles. However, the Conservatives cannot simply rely on the Prime Minister's unpopularity. They have to sharpen up their own policies too.

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