ONE has humbly to ask if the Tories are now seeking political advice from Alan Partridge.

The question arises after the Conservative leadership unveiled a new ruse, underlining how that most sensitive of subjects, immigration, will now be at the forefront of their bid to win power at the next General Election.

It's true, few of us had any doubt that the subject would feature highly on the Tory election agenda, but the intriguing sight of poster vans touring North London confirmed just how hard David Cameron will push the issue up to May 2015. Tory rightwingers like Boris Johnson praised the campaign - showing handcuffs and declaring: "Go home or face arrest" - as not racist but blunt and uncompromising, no doubt believing the posters would remind the UK capital's illegal immigrants of their unlawful status, prompt them to text the Government number and make their way in good order to the awaiting plane to take them back whence they came.

Mark Harper, the Conservative Immigration Minister, turned on the poster van critics, insisting they were encouraging illegal immigrants in their law-breaking. Perhaps trailing an election argument to come, he added, curiously, that immigration had, in fact, not had the economic benefits some had claimed, insisting there was evidence it had pushed down wages for low-skilled jobs.

What rings more true about van-gate is that this was simply an exercise in dog-whistle politics a la Michael Howard in 2005 but this time aimed at Tory-turned Ukip voters, who might, seeing the publicity, agree that the legion of illegal immigrants should be told in no uncertain terms to get off the luxury liner that is the United King­dom.

Of course, in Scotland where the demographic timebomb is ticking, there is probably a need for more immi­grants to help pay for the welfare bill.

One of the more interesting aspects of this furore was that the Tories' Liberal Democrat Coalition partners - including Jeremy Browne, a Home Office Minister - were not even told of the poster vans pilot. Vince Cable, the LibDem Business Secretary, branded the campaign "stupid and offensive".

Nick Clegg, a little more restrained, said it was "not a clever way of dealing with" illegal immigration and that exit checks were a much more effective idea. "What," he asked, "are we going to have next? Home Office vans going around saying: 'Please don't shoplift. Please don't steal this car?'"

Amid the wave of criticism, Downing Street noted, with a straight face, how the poster campaign was attracting a "great deal of interest", that it was "already working" and might even be rolled out across the country.

A disbelieving Labour Party referred the matter to the advertising watchdog, saying it was grossly misleading because the claim on the poster of "106 arrests last week in your area" included Heathrow Airport, which cannot be said to be in North London. Meanwhile, the union Unite was consulting lawyers on whether the poster vans incited racial hatred. Its leader, Len McClus­key, branded them "vans of hate".

What, one has to ask, is Tory HQ's next wheeze? Sending poster vans down Sauchiehall Street showing a Prime Minister in a Union Jack kilt urging Scots to vote to stay in the UK?

A-ha!