I love the UK! Not only because I am married to a Brit, nor because my children are dual nationals of the UK and Finland, but because Britain stands for values I hold dear.

Reason, individual rights, freedom, pragmatism, openness, opportunity, free trade, democracy – all of these are ideals that Britain has defended and promoted, sometimes at great cost, but always with the conviction that values are worth fighting for.

But when I look at the British debate on Europe I sometimes wonder where these qualities are. Pragmatism seems to have surrendered to ideology, openness to barriers, confidence to mistrust.

Prime Minister David Cameron wants to negotiate Britain’s membership to the EU. That will be difficult. Ed Miliband, leader of the Labour party, wants a referendum if more competence is transferred to Brussels. That is not on the cards. Liberal Democrat leader Nick Clegg wants to maintain a reformed EU with existing powers. So do I. Nigel Farage of the UK Independence party wants the UK to leave the EU. That would be a travesty for all of us.

The UK is one of the most civilised nations in the world; yet it has the most uncivilised EU debate in Europe. Few are the voices prepared to extol the benefits of EU membership. Plenty are those that distort Britain’s role in Europe.

I believe the EU and the UK need each other. Britain has always made a great contribution to EU policies. And membership has always been of great benefit to Britain. The single market, free trade, fiscal restraint, enlargement, foreign policy and competitiveness are all areas in which the UK has made a decisive impact. At the same time British industry and the City of London depend on European markets.

I understand the idea that Britain’s uneasy relationship with the EU should be tackled head on, and resolved for good by putting the question of membership to the public. But this is not a step that should be taken lightly. It could lead to an outcome that would do irrevocable harm for both Britain and the union: the exit of Britain from the EU. This is a debate that needs to be carefully framed by facts and realities.

The idea of a renegotiation of membership – or, as it is sometimes put, the “repatriation” of powers – is taken seriously in Britain. It rests on the assumption that the EU treaties would be open for renegotiation. I think this assumption is misplaced, for three reasons.

First, there is a practical problem. Renegotiating a treaty with 28 signatories would be immensely complicated – not to say impossible. There will be 28 different views on what to do.

True, the EU must evolve. But this needs to happen through pragmatic steps aimed at increasing growth and creating jobs, not sudden and wholesale change.

Second, while it may once have been assumed that treaty change was needed anyway to fix the institutions of the eurozone, events have demonstrated that this is not the case. Economic governance is being strengthened within existing treaties. The real issue is growth, not institutional tinkering.

And, third, the EU is a club. The benefits and responsibilities of membership have to be taken as a package; there is no a la carte menu on the table. The idea that a single member would be allowed to pick and choose the policies it wants is not realistic. If we all could opt out at will from individual policies we dislike, there would not be much of a union left.

What kind of participation in EU institutions does the UK envisage? The single market only? Well, there is the European Economic Area, which encompasses Norway, Iceland and Liechtenstein as well as the 27 EU states. But we have to be very clear about how the EEA works in practice. Membership makes you part of the single market but you have no say in the rules that govern it. And this is not a free lunch either; EEA members have to make a financial contributions to the EU budget without receiving a rebate.

To me things look messy. The UK seems to be in a vicious spiral of self-inflicted marginalisation. All of these questions are diminishing British influence in Europe and the world. None seem to be in Britain’s interests. All this talk of referendums and “locks”, as promised this week by Mr Miliband, is worrying. What if someone just throws away the key?

The UK has argued for EU reform – making sure its institutions promote growth, create jobs and contribute to competitiveness. Here, Britain is absolutely correct. The EU needs to get this right. Global competition is more demanding than ever. In 2014 we choose a new European Commission, and we need to ensure it focuses on these issues.

I believe that Britain has a better future as a full partner in the EU. But this is a decision for Britain and the British people alone.

We economic liberals and free traders want to stay married to Britain in the EU. Therefore we should say Yes to reform but No to renegotiation of treaties.

The writer is minister for European affairs and foreign trade of Finland.