As yet, the opposition are not threatening them on the issue – Labour still find it easiest to get noticed when they are apologising for their own record – and the general thrust of the Conservative approach, that immigration has been too high and must be reduced, is clearly very popular.
But they have two problems. First, hardly anyone believes the government will actually deliver on their promises. A recent YouGov poll found 78 per cent believe it unlikely they would succeed in reducing annual net migration "from the hundreds of thousands to the tens of thousands".
Second, while the general idea of reducing immigration is popular, there is far less public support for the way the government is going about it. This is the main value of today's survey. It finds only a minority (32 per cent) support reducing the numbers of either foreign students or high-skill migrants – the policies the government is actually pursuing.
The strongest support (64 per cent) is for reducing the numbers of low-skill migrants; but for many years now, the great majority of low-skill migrants have come from the EU, which the government can do nothing about. Indeed, the most recent figures show net migration from Eastern Europe increasing. (There is also strong support for reducing illegal migration, asylum seekers, and extended family members coming from abroad; though in the latter two cases, this is likely to be based on an exaggerated view of the numbers.)
This picture confirms what some of us have been saying for a while: not only is it dangerous for politicians to promise what they can't deliver, especially on an issue as emotive as immigration, it is perverse to end up targeting those categories of immigration which are the least unpopular, simply because they are the easiest to cut. It is especially perverse in the current economic climate, given that these categories are the most economically valuable.
The minister who has the job of trying to manage these contradictions is Damian Green. He is neither stupid nor an ideologue, and it is said that privately he chafes against the net migration target. He has been experimenting with a different narrative: that net migration was "increasing relentlessly" until the election, and that the government should be given credit for stabilising it, even if they haven’t been able to reduce it. Unfortunately for him, the UK Statistics Authority has stated for the record that they "do not see evidence of an upward trend since 2004", and that they "would not regard the end of 2010 as the point at which the figures levelled off".
A better approach would be to follow the advice of the Migration Observatory, and abandon the crude target on net migration in favour of a wider range of indicators. In turn, this would allow the government to begin a longer term process of realigning their policy and language.
They should start by focusing on illegal migration. Today's survey finds that among the 69 per cent who say immigration should be reduced, a majority say the reduction should come "only" or "mostly" from illegal immigration; yet at the moment, the government's efforts in this area amount to little more than a new "shop-an-illegal" helpline, alongside cuts to border staff.
Next, the government should shift its approach to the categories of legal immigration which today's survey shows people are least bothered about: high-skill migrants and foreign students, where in each case a majority think the numbers should increase or stay the same.
On foreign students, Australia has just reversed their own restrictive approach, concerned at the damage to university revenue and the loss of export earnings. I have argued that the UK government should follow suit, concentrating on tackling visa scams and bogus colleges, but separating this from the numbers game of the net migration target – especially since only a small minority of foreign students stay permanently anyway. Today's survey confirms that despite foreign students making up the largest category of immigrants (37 per cent) on the government's chosen definition, they are seldom what people think of when they think about immigration. (People are still most likely to think about asylum seekers, despite the fact that for the last five years they have made up only 5 per cent of immigration – a damaging legacy of the asylum crisis of a decade ago, and the way the media covered it.)
On high-skill migrants, the government should abandon the idea of a further reduction in the quota, which David Cameron trailed in his speech last week, and move away from the crude and unfair emphasis on wealth, which in a lengthy analysis I identified as another big distorting influence across the range of current immigration policy. As I argued, it is hard to identify the next generation of entrepreneurs or Nobel laureates – and it certainly can't be done by looking at how much they are currently paid. The history of migration is one of talented, motivated people who start from fairly humble beginnings, and spend years working hard and making sacrifices for themselves and their family. It can take many years before this pays off, but when it does, it can do so spectacularly, for them and for the society which has offered them a home.
It is to Cameron's credit that he leavens his generally negative language on immigration by reminding people of the enormous contribution it has made to Britain in the past. But without a major change in policy, it will be significantly less likely to do so in the future.
Matt Cavanagh is an Associate Director at IPPR.