This week, the heads of the 28 member states of the European Union met to discuss possible reforms to the EU proposed by British Prime Minister David Cameron.

Since his government took office in May, Cameron has called for a “better deal for Britain.” In several speeches and his recent letter to the president of the European Council, Cameron said that he wants a more flexible EU that would allow member states more control over EU legislation and the ability to limit social benefits for migrants.

Cameron has also pledged to hold a referendum in which British voters could choose whether to remain in the EU. This raises the question: What kinds of reforms to the EU would British voters support?

Our new study addresses this question. In a survey of 12,000 Europeans, we conducted an experiment in which respondents evaluated reform proposals that differed in four respects.

  • Who should make decisions in the Union? Should European institutions like the Parliament, Commission or even a directly elected European president decide, or rather national governments?
  • How many member states should the Union have — the current 28, less or even more?
  • What should the EU’s main policy goal be? Should it secure peace, promote economic growth or expand/limit intra-EU migration?
  • How much should individual citizens contribute per year via taxes to ensure that the Union can operate fully, roughly 70 Euros like the British pay today, less or more?

One unsurprising finding is that British citizens favor a union that is cheaper, with an annual contribution that is lower than the current €67.

In addition, they favor decision-making by national governments or via EU referenda over those taken by the European Parliament. This factor appears to be more important to British citizens than the annual contribution, therefore supporting Cameron’s statement that the British people want a more democratically accountable and responsive EU.

In terms of preferred policy goals, the British favor a union that secures peace and security, followed by one that deals with immigration and brings economic growth.

Finally, the British are indifferent when it comes to the number of member states of the Union; they only clearly oppose a very small Union of only six member states.

The attitudes of the British differ substantially from those of other EU citizens. Elsewhere in the EU, citizens do not necessarily favor decision-making by the national governments or via EU referenda over decision-making by European institutions. And while British citizens tend to support an EU that would restrict intra-EU immigration, other Europeans tend to oppose it.

Within Britain, concern about immigration and the desire to move decision-making away from the European Parliament is particularly strong among those who favor withdrawing from the EU. Those who prefer to remain in the EU prioritize peace and security and are indifferent about whether decision-making is located in EU institutions or national governments.

What might these results mean for Cameron’s negotiation efforts? Two things stand out.

First, many British people want more national control, but other Europeans don’t. So if European leaders were to move to more national governmental control to appease the British, they might suffer political consequences at home.

Second, Cameron faces his own balancing act. British Euroskeptics value an EU that regulates immigration, even more important than a Union that would promote economic growth. But by catering to the preferences of Euroskeptics, Cameron might alienate British citizens who support the EU and have very different priorities for the EU. This is a real risk: 59 percent of British respondents in our survey favored remaining in the EU.

In short, our study shows that Cameron faces quite treacherous politics as he negotiates for EU reform both with other EU leaders and with his constituents back home.

Catherine E. De Vries is professor of European politics at the University of Oxford. Isabell Hoffmann is a project manager at the Bertelsmann Foundation.