Two months ago, when British politics was all about European parliamentary elections, Nigel Farage was everywhere. The Ukip leader made immigration the big campaign question and inserted himself into the answer. Since then, he has been relatively quiet.

He popped up in the Telegraph a couple of days ago to heap scorn on David Cameron’s announcement of yet another tightening of the rules applied to immigrants claiming benefits. But by the standards of Farage’s frenetic work rate, a sneering op-ed accusing the prime minister of missing the point is a day off.

A small party such as Ukip once had to clamour for attention, setting off provocative fireworks to be noticed. Now the balance of power has shifted. The mainstream – specifically the Conservative party – keeps the Farageist fire burning when Farage himself is otherwise engaged. So it is hardly surprising when a new survey shows around a third of Tory voters preferring the idea of a coalition with Ukip after the next election to a continuation of the existing arrangement with the Liberal Democrats.

The Conservative leadership has done everything in its power to signal affinity with those voters currently tempted to back Farage. At one level this is rational politics. Cameron is losing support to Ukip and he needs to win it back. Ramping up the rhetoric against benefit-snaffling immigrants has, in theory, the additional benefit of making the Labour party uncomfortable.

This is a strategic gambit that comes direct from the playbook of Lynton Crosby, Cameron’s Australian campaign director. Crosby has a graph showing, on one axis, issues that people care passionately about at one end and care little about at the other end. On the other axis are issues where voters think the Tories are strong at one end and weak at the other. So for example, the NHS is something people care about but don’t trust Conservatives to sort out. Clamping down on benefits is also something people care about but happen to think Tories are rather good at. It follows then that an election campaign should aggressively target the bits of the graph where there is a happy confluence of public anxiety and confidence in Cameron. Other issues must be closed down.

The problem with this approach is that it presumes voters who are angry about an issue have nowhere to go but to their least despised option. This is the case in Australia where there are two big parties and voting is compulsory. In the UK, voters who are animated by resentment of foreign infiltration can stay at home on polling day or back Ukip. So one possible effect of Cameron dancing to Farage’s tune is that it keeps the tune in people’s heads – even when Farage isn’t around to whistle it – while also reminding them how little expectation they have that the prime minister will get the moves right.

The effect of all this is to send a signal that Ukip concerns are the right ones but that the current Conservative leadership is unable to deliver the goods. Or, in short: if you like what Ukip has to say, vote Ukip, which is why Farage can spend some time in bed and let Cameron do a summer campaign for him.

The counter-argument from the Tories is that Farage’s vote will collapse next May when voters are seriously contemplating who to put in government. There is still plenty of nuttiness and fruitcakery around in the Ukip ranks to make reasonable voters recoil. Farage will have his work cut out assembling an army of several hundred prospective parliamentary candidates, none of whom has a lurid past in neo-Nazi agitation, petty crime or vile rhetoric. And Conservative headquarters will strive to expose every Ukip loony it can find.

So the Crosby approach may yet do the trick, in the sense that it may galvanise just enough angry Tories and Ukip waverers to get behind Cameron on polling day for the party to emerge with more seats than Labour in a hung parliament. It is plainly not a strategy for winning a broad-church majority. For that, the party would have to strive once again to shed the “nasty party” residue that clings to its brand. Craven aping of Ukip’s agenda takes it in the opposite direction.

This, ultimately, is why Tories who care about their party’s health should be anxious about the current strategy. The Australian pugilist is being paid for one thing only: to get Cameron over the finish line a step ahead of Ed Miliband.

It could work. Labour is obviously beatable. The Tories might scrape through and hold on to Downing Street for another term. But a heavy price will have been paid in terms of long-term electability and moral credibility. Crosby will be banking his fat cheque for services rendered, looking for his next gig, while the task of decontaminating Toryism as a majoritarian project will have to begin all over again.