Immigration is a convenient coalition punchbag

Wait a minute. When the business secretary says the prime minister is "inflating extremism", you know something very odd is going on.

We all know the context, of course, which is that this isn't just any government. This is a coalition. And, even though the great work of running the country must go on, there are elections in the offing.

Let's just savour those outspoken Cable comments once again. "Talk of mass immigration risks inflaming the extremism to which he and I are both strongly opposed," Cable said this morning, in response to the text of a David Cameron speech on immigration. The PM is underlining his commitment to reduce immigration from the hundreds of thousands to the tens of thousands. The language he is using to do so is soft and cuddly: "I believe the role of politicians is to cut through the extremes of this debate and approach the subject sensibly and reasonably." But the bold Tory approach has prompted fears about the moves hitting the economic recovery. The Lib Dems don't like it one bit.

Rather than keeping quiet, Cable has spoken out in a way which truly is inflammatory. His comments bring the ongoing rumbling internal row over immigration to the front and centre of the political agenda. Yet again (remember bigotgate?) immigration steals an electioneering march over the everyday issues which dominate the lives of those in Westminster.

This is no coincidence. Parliament is in recess, so Britain's politicians are spending April out on the doorstep. They're hearing the perennial concerns about what Cameron calls the "hugely emotive subject" which dominates ordinary people's worries. Ministers continue to struggle with the enormous gap which exists between their mainstream, pragmatic approach and the views of ordinary British people - sometimes acceptable, sometimes disgustingly not so. Last year the Tories managed to bridge this gulf most effectively. Now they are trying to repeat the trick.

There's just three weeks to go until local elections, when the Conservatives must try to defend their dominance of local government up and down the country. This was the audience Cameron's speech was targeted at: he made very clear that, when it comes to immigration at least, the government's approach is a Conservative, not a coalition one. Everyone understands this; even Cable, who preceded the remarks quoted above by saying: "I do understand there is an election coming, but..."

The business secretary is not like most politicians, in that he displays a refreshing willingness to air views which most ministers would keep firmly to themselves. It's what some people call 'courage' - he is a thorn in the prime minister's side, even despite nearly losing his job before Christmas over the BSkyB merger. Whether he knows what he's doing is, to some extent, immaterial.

In a poorly-reported speech in the north of England today, Lib Dem deputy leader Simon Hughes has admitted that his party "took us some time after May to get our act together". He shies away from descriptions of the coalition as a "marriage" or a "love affair", instead preferring to call it a "practical business relationship". We will see this language appear more and more in the final year of the coalition's five-year term. What's happening now is a sneak preview - when the need to win voters' support temporarily overrides the prevailing pressure to demonstrate government stability and unity. What better issue to pick a fight over in the spring of 2011 than immigration?