Howard used his dog whistle, but then Blair bared his teeth

Hands up those who want immigration to be a central theme of the Conservative campaign. Paul Dacre, editor of the Daily Mail, I see his hand shoot up at the front. Peter Hill, editor of the Daily Express, I see him trying to outdo Dacre. Who's that at the back? Tony Blair? Alastair Campbell? The very same.

Hands up those who want immigration to be a central theme of the Conservative campaign. Paul Dacre, editor of the Daily Mail, I see his hand shoot up at the front. Peter Hill, editor of the Daily Express, I see him trying to outdo Dacre. Who's that at the back? Tony Blair? Alastair Campbell? The very same.

In fact, the last person to want immigration to be the most important issue of the campaign is Michael Howard. Of course, he is not exactly sitting on his hands. "Controlled immigration" is one of the six phrases scrawled on the cover of the Conservative manifesto. The Conservatives want to make an issue of asylum and immigration. It helps to motivate their core vote, and it may bring them a tiny sliver of uncommitted voters who would not otherwise vote Tory. But they do not want it to dominate their campaign. It makes them look, as Blair put it in Dover on Friday, like a "one-issue" party rather than a "one-nation" party.

The fact that immigration is the second election issue after the health service in our poll today is alarming, but it will do the Tories little good. I suspect that there are two reasons why the issue has been so prominent. One is that there is not much else happening. There have been no shockingly untypical NHS cases since Margaret Dixon had her shoulder fixed last month and survived the daunting odds. The Deputy Prime Minister hasn't hit anyone. The new Pope has not issued an encyclical saying "Vote Conservative". The second is that the priorities of the liberal media have influenced how this vacuum is filled. It was not Howard's idea to fill the front page of The Independent with the unlovely words of Tory candidates such as Robert Spink of Castle Point: "What bit of 'send them back' don't you understand, Mr Blair?" Nor was it his idea to devote the first third or so of his interview with Jeremy Paxman to the subject.

Howard is less in control of the Conservative message than is often assumed, as was well illustrated at Easter, just before the formal campaign began. He was accused of copying the tactics of the religious right in America by "making abortion an election issue". He gave an interview with Cosmopolitan magazine that was seized on by Cardinal Cormac Murphy-O'Connor, the leader of the Roman Catholic church in England. The cardinal said that the policy supported by Howard, of cutting the time limit for abortions from 24 weeks to 20, "is one that we would also commend".

Cue much outrage about the improper use of religion in politics. But it was all a mistake. Howard's people explained vainly that he was asked a question and answered it. I believe them, not least because Howard claimed to Cosmo that he had voted to reduce the limit to 22 weeks in the past - whereas he had voted against 22 weeks when the limit was reduced to 24 weeks in 1990.

So the real story was that the Tory leader answered an unexpected question in a "soft" interview by expressing the common view that advances in medical technology require a change in the law, and misremembered his past voting. That did not stop Labour politicians and press commentators from uniting to condemn the use of abortion as a "dog whistle" issue. The phrase, popular in Australia whence the Tory campaign chief Lynton Crosby was imported, means one that can reach voters who care about it without being heard by the rest. Some dog whistle: the abortion fuss rumbled on for the whole of Holy Week.

Immigration is also sometimes carelessly described as a dog-whistle issue, despite the fact that the shrill blast has been clearly audible throughout the campaign. Indeed, the Conservatives should want it to be a lot more dog-whistlish than it is. They know that they cannot win a national election on it. It may be glib to say that Howard is simply rerunning William Hague's 2001 campaign, because anti-European sentiment was a bigger part of the xenophobic mix four years ago, and the campaign this time is better run. But it remains true that immigration is an issue that does not drive the vote. Certainly not when you are up against such a confident and ruthless opponent as Tony Blair.

The Prime Minister's speech in Dover was one of his best of the campaign. It sounded tough enough to put liberals' teeth on edge but, with the exception of identity cards, it did not cross any sacred lines. I do not much like Blair's use of Tory language of "border" controls. The only border the UK has runs from Donegal to Dundalk Bay, and it is rather heavily policed already. But there is an election on and this is no time for pedantry. The substance is what matters and Blair had fun with the Tory pledge of "24-hour surveillance at our ports". There are 650 of them, and it would be expensive to maintain a round-the-clock fingerprinting presence on every beach.

Then, with relish, the Prime Minister took us off on a tour of "fantasy island", the unidentified offshore location where asylum applications would be processed under the Tories. A policy that would be paid for by plainly mythical savings from the immigration budget.

The speech served two purposes from Blair's point of view. He was meeting the challenge head on, and he was helping to keep the subject centre stage, safe in the knowledge that there are no further votes in it for the Tories.

The fragility of Tory policy when held up to anything resembling the real world is extraordinary. Surely if Howard intended immigration to be so central, he would have done his homework better. Or perhaps not. It is not as if Tory policies on tax and public services - issues that might actually be capable of driving an electoral breakthrough - can withstand much scrutiny. The final tax cut announced last week at the end of the dance of the three veils was patently the wrong choice. Gordon Brown just about got away with raising the stamp duty threshold to £120,000 in the Budget last month, because economists were slow to point out that prices would simply rise to make up the difference. They were quicker to make the point when Howard announced the Tory plan to raise the threshold to £250,000. All that would do is reduce tax revenue, slightly enrich some existing home owners and help precisely no first-time buyers at all.

If that was Howard's last shot on the central territory of tax and spend, then no wonder the media are inclined to veer back to immigration where strength of feeling, pro and anti, at least makes up for lack of policy. Not that journalists can be blamed for misinterpreting Howard's intentions. But immigration and Gypsies were always subsidiary to the central Tory strategy, which is to try to persuade us that the Tories can deliver better public services where Labour has disappointed. The prominence of immigration is a measure of the failure, rather than the success, of the Conservative campaign.