Bruce Anderson: The Tories should be doing better in the polls, but that is no reason to change tactics

Tory modernisers believe the party's popularity problems are not recent but go back at least 40 years

Despite committing every form of self-harm short of injecting themselves with bird flu, the Liberals have not suffered in the polls. Labour are looking confused, ropy, sleazy, burnt-out and divided - yet instead of being 10 points behind, they are level with the Tories. So some of Mr Cameron's supporters have started to grumble.

This does not dismay him; it does not even surprise him. Mr Cameron and his closer advisers are committed to a strategy. Determined to change the public's perception of the Tory party, they never believed this could be accomplished in a matter of weeks. Far from discouraging them, the loss of momentum will only incite them to press on harder.

The Tory modernisers have a powerful case. They believe that their party's popularity problems are not a recent phenomenon but go back at least 40 years. In 1964, the Tories won 43.4 per cent of the vote, when the unjustly derided Alec Douglas-Home was up against the unjustly respected Harold Wilson. Since then, in far more favourable circumstances, the Tories have struggled to emulate Sir Alec.

There are two explanations for this: toffs and Thatcherism. Toryism is widely seen as a political creed for the well-off, who do not have to worry about next month's bills, still less the state of the local NHS and local schools, which they would never dream of using. Then along comes Maggie. She may not be a toff but her political body language reinforced the message that the Tories do not care. However much money she spent, she always gave the impression that she would rather be cutting. This did not matter too much as long as the Tories were only up against Michael Foot and Neil Kinnock, but, once Labour changed and seemed to be offering the voters the compassionate, centrist government which many of them had always wanted, the Tories were in trouble.

David Cameron wants to get them out of trouble and is convinced that this cannot be done either by returning to traditional Tory themes or by unleashing the economic radicals. If the Tories were to talk about crime, immigration or Europe, the public would not think: "We agree with that." They would think: "Oh, the Tories; we don't trust them." If some clever youngster from a think-tank produced a plan to reform the health service, the voters would not respond: "Good - about time the NHS became more efficient." They would say: "When the Tories talk about reforms, they mean cuts."

Most of those who are involved with implementing the Cameron strategy are radicals both by instinct and by intellectual conviction. George Osborne, Oliver Letwin, William Hague, Michael Gove, Steve Hilton, George Bridges, Francis Maude: none of them came from the left of the party and all of them would naturally believe in lower taxes and a smaller state. But they have been persuaded that the party must win the battle for trust before it can fight the battle of ideas.

There is only one alternative to Mr Cameron's strategy: to renew the search for the silent majority. Anyone who has ever canvassed for the Tories in a working-class area will understand the temptation. There are many voters whose views on Europe, immigration, asylum and crime - issues which often seem to meld into one - are, as it were, robust. Tony Blair and David Blunkett have met the same voters, judging by their rhetoric (if not their actions).

In the US, the Republican Party has turned itself into a formidable election winner by breaking out from its affluent base and using cultural issues to win over Joe Sixpack. What is to stop the Tories doing likewise?

There is a simple answer to that: a great deal. In the first place, Britain is not the US. Think how inconceivable it would be that abortion could ever become a major electoral issue over here. Second, consider the outcome of the canvassing efforts on the doorstep. In the great majority of cases, after sounding well to the right of the BNP, the householder will announce his intention of voting Labour. There may be many fewer high-minded centrists than there are silent majoritarians. But it is much easier to alienate the former than it is to win over the latter.

There is absolutely no evidence of a great swath of voters desperate to support a populist Tory party. If there had been, Mrs Thatcher would have won them over and built up an indomitable percentage lead, instead of struggling to stay at Alec Home's level. In Britain, as opposed to the US, the silent majority has proved that it is good - at remaining silent.

There is a further reason for discounting the impact of cultural issues; economic insecurity, as it affects potential Tory middle-class voters. The British middle class is much better off than its forbears were, except in one respect. Though the middle classes of the Fifties and Sixties enjoyed many fewer luxuries, the current generation might swap a lot of those for the one luxury of a safe job. Forty years ago, millions of 40-year-old middle-class men knew that, unless they raped the chairman's daughter while robbing the petty cash, they had a job until they were 65. Today, there is hardly anyone in the private sector who can make that assumption.

If people are insecure, they are more likely to vote on the economy and to vote for politicians whom they trust. However much noise they make on Europe, crime et al, they will support the party which they regard as more likely to safeguard their standard of living. That is why David Cameron has concentrated on trust-building rhetoric rather than rushing into policy pronouncements. He wants to ensure that, when he does produce the policies, he will receive a hearing.

All this has been well thought out. It is a complex strategy, not simply an attempt to appear pleasant. Any Tory who is inclined to question the Cameron approach should begin by asking himself whether there is a realistic alternative.

There is one further factor, or rather, I fear that there will be. We will be fortunate indeed if there is not a further terrorist onslaught on the UK between now and the election. If that does occur, the way in which the politicians respond will have a profound effect on the public's view of them. No one can predict either the circumstances or the outcome. It is to be hoped that we never find out how the various party leaders would have reacted, and the voters will have to make their choice on the usual issues. If so, Mr Cameron is positioning his party to receive a favourable verdict.