How Britain can restore freedom to Europe It would be better to use the crisis to construct something more enduring: a new model for the future of the EU itself. The 2010 Conservative manifesto promised to repatriate EU powers in three areas. This was blocked by the Lib Dems, but the Tories remain committed to such a treaty renegotiation. Yet opting out of certain EU policy areas is not a comprehensive solution. Opt-outs are vulnerable to the federalising bias of the European Court of Justice (ECJ). The Working Time directive was imposed by majority voting - under health and safety provisions - even though the Conservative government had an opt-out from the Social Chapter at the time. Instead of relying on a limited number of insecure opt-outs, we should turn the system around and create a Europe of opt-ins, whereby nothing is binding unless explicitly agreed. There is one area where the UK already participates on this basis: justice and home affairs. These policies were originally decided government-to-government, but the Lisbon Treaty moved them over to majority voting and full involvement of the ECJ. However, the UK has retained the right to opt in to such measures on a case-by-case basis. It does not just apply to future EU laws; in 2014 the UK can choose to repeal past ones, too. This process of collective discussion and negotiation, followed by a national decision on whether to participate, is the right model for EU engagement. It is different from a veto, because countries choosing not to join would not prevent others from doing so. The same opt-in procedure would apply in every other policy area, including social and employment legislation, the environment, foreign aid, energy and transport. All powers would be repatriated and then used selectively. Is there an exception, where compulsory rules are necessary? Yes, and it covers the requirements for free trade. The advantages of tariff-free trade in the EU are now much less than when we joined in 1973. But if we were outside the single market we would face steep duties in some sectors, such as cars and chemicals. The single market also brings protection from complex "rules of origin" tests for our exporters. Given the huge trade deficit the UK runs with other EU countries, it would be in their interests as well as ours to keep the present arrangement. These rules, strictly limited to what is essential for trade, would be the core discipline, and on that foundation all other agreements would be built, case by case, according to the opt-in principle. The euro crisis provides the opportunity for the UK to assert its claims on how decisions are made. The European Fiscal Union requires British agreement to the use of EU institutions. Current negotiations on the EU budget for 2014-20 also give the UK huge leverage, since the outcome must be agreed unanimously. Another opportunity to negotiate from strength was provided by the call last month from José Manuel Barroso, president of the European Commission, for EU treaty change. The matter can only be settled by a mainstream party of government obtaining an electoral mandate and then putting the subsequent treaty to the people in a referendum. For the Conservative Party, this would not be a retreat from modernisation or the wider world. On the contrary, it is the EU which is old-fashioned, remote and visibly failing as a global influence. It would be a liberating experience for Britain to once again take up the cause of democracy and freedom in Europe. It will require huge determination and will, but those who deliver this would rise above the managerial concerns of government and earn a place in history. David Heathcoat-Amory is a former minister for Europe and the author of 'The UK and the EU: cutting the knot," a Centre for Policy Studies paper to be published at the Conservative Party Conference