A just way to manage migration An outright cap on free movement, however, would not be in the UK's best interests. In any case, even though much reform can be while achieved while Britain remains a part of Europe, this is where other leaders would most likely draw the line. And even if Britain were outside the EU, it would struggle to implement such a policy. Both Switzerland and Norway are required to accept free movement of labour as the price for trading with the EU. These two countries now take in more EU migrants per head than the UK. It is no small irony that under Ukip's flagship policy - that Britain should become more like Switzerland - we would be home to four times as many EU migrants as we are today. The answer, then, surely lies elsewhere and I think I know where. In my view, David Cameron should keep free movement along with the benefits it brings, but repatriate control over who can have access to the UK's welfare system. I'm not talking about "benefits tourists" because only 2.5 per cent of the total unemployment benefits claimants in the UK are EU migrants. For the most part, people come to Britain to work, and they generally do an excellent job. No, the main issue is the generosity of the UK's in-work benefits. One of the key advantages of free movement on an open economy is to help keep wages and therefore production costs low, which boosts our competitiveness. However, this is exactly what many regard as being a key problem. Downward pressure on wages has a disproportionate impact on native workers at the lower end of the pay scale. Opinion polls show that this is what voters are most concerned about - a majority are in favour of "high-skilled migrants" but oppose the "low-skilled." The good news, however, is that there's a balance there to be struck. Unlike the vast majority of EU countries, the UK makes in-work benefits - tax credits, social housing and access to the NHS - immediately available to EU migrants. In contrast to out-of-work benefits, EU migrants are marginally more likely to claim in-work benefits. EU migrants make up 5.56 per cent of the UK workforce, but families with at least one EU migrant make up 7.7 per cent of in-work tax credit claims. The UK's in-work benefit system effectively acts as a sort of "taxpayer-backed subsidy" for European workers to perform low-paid jobs here. In some cases, take-home pay is topped up by almost two-thirds. In many cases, it pays to go from an average-paid job elsewhere in the EU to a minimum-wage job in the UK. Which is why, in a report published by Open Europe today, we propose new rules which would allow national governments to limit EU migrants" access to such benefits. This would have a radical impact. For example, it would halve the financial incentive for a single worker from Poland to come here to work on the minimum wage, while the average weekly income would drop by 8 per cent for a Spanish worker in a similar situation. A Polish single earner with two dependent children would see their average weekly income drop by 27 per cent if they were to move to Britain, while under the present rulings, it would nearly double. Taking away this in-work subsidy would be a neat way of addressing the public's most pressing concerns about EU migration, but without ending free movement. True, such a change would require the approval of other European leaders, but unlike an outright cap it is not a full-scale treaty change. It might draw support from elsewhere in Europe. The Danes, Germans, Dutch, Austrians and even the Swedes, for example, have concerns over free movement. It certainly could, in the long term, prove more effective at bringing down the overall number of immigrants than the other ideas under consideration. The emergency brake, for example, might just be negotiable in Europe. It would allow the UK to temporarily restrict EU migration if it reached a certain level. However, there are two problems with this: first, finding the right criteria (you can hardly claim an "emergency" if your economy is the best performing in Europe); secondly, will it serve to reduce the long-term flow of immigration? Before we rush to legislate, British politicians and voters should bear in mind that such policies aren't free of consequences. Fewer EU migrants could even make the UK economy less competitive overall. In the run up to a general election, particularly an unpredictable one, knee-jerk policy-making is a fast way to a disenchanted electorate. This is time for clear-headed consideration. Writing the policy headline first, and the content later, doesn't work. Mats Persson is director of the think tank Open Europe