In his recent speech to the Lib Dem Spring Conference, Ed Davey reminded us of one way in which the Lib Dems stand out from other parties. He said the Lib Dems were ‘The only party that has consistently opposed the Conservatives’ damaging Brexit deal from the start. The only party arguing for a new deal with the EU, with a Customs Union at its heart – putting us on a path back to the Single Market.’

In this as in so many other areas of policy, the Lib Dems have the courage that Labour lacks. Returning to the Single Market might seem like too bold a policy, but in fact it is essential to the future of the UK.

It is essential to its economic future. As Rachel Reeves struggles with a terrible economic inheritance from the Tories, Brexit remains a part of that inheritance, though it is one she keeps rather quiet about. The dreams of economic prosperity free of the rules of the Single Market, mopping up lucrative trade deals with Australia, India and the USA (Trump’s America? Really?) and turning the country into some kind of Singapore-on-Thames have faded away. Instead, the UK must struggle with new rules and regulations interfering with the business it tries to do with its nearest neighbours now that it’s out of the EU. There’s a clear cost in terms of growth – just ask Mark Carney, the former Governor of the Bank of England and now Prime Minister of Canada.

Returning to the Single Market is also essential to the UK’s political future. The problems managing trade across a land border with Ireland, a country which is part of the Single Market, have not gone away.

Thirdly, a return to the Single Market will help the future of Europe. A larger Single Market will be a more effective negotiator and will be in a stronger position to resist the threat of a present or future tariff war.

It’s worth remembering the example of Norway, which chose to stay out of the European Economic Community in 1973 but remains part of the Single Market. Yes, that does mean it contributes to the EU budget, but the economic gains of market membership far outweigh the costs of its contributions. Yes, it does mean having to abide by the rules of the market, but that is simply part of any commercial relationship involving nearly thirty different countries. And it’s worth remembering that Norway, with its two-thousand-mile coastline, was not prepared to accept the Common Fisheries Policy and the Common Agricultural Policy. Neither of these apply to Norway despite its membership of the Single Market. The UK’s farmers and fishers could avoid those controversial policies if the UK adopted a Norwegian-style arrangement.

Some people will say that immigration is the fly in the ointment. What about the rules for the free movement of people within the Single Market? Of course, these rules make sense – if you’re in a single market, you expect to be able to look for work inside it, as more than a million UK expats understood pre-Brexit (migration is a two-way process). But whatever people’s views of current levels of immigration, it’s clear that Brexit has not stopped numbers rising and has done nothing to lower the tone of this often-poisonous debate.

I admit to the self-interest of someone who has lived out of the UK for a long time – in Prague for 13 years and in Brussels for 20 years. But from the perspective of living abroad it seems to me that there never was a more crucial time for recognising our identity as a European country, part of a continent we can move about in freely, a continent facing threats from both West and East. So many educational and scientific programmes across borders – Erasmus, Horizon and so on – should be benefiting the UK. How can Reeves trumpet an Oxbridge Silicon Valley and yet not embrace these programmes? So many students should be going in both directions with ease to study and do important research. Travel to other parts of Europe should be made easier rather than more difficult, as it is fast becoming. Instead, this government seems to think that growth will come out of extra planes over Heathrow or even a giant circus tent to restore the fortunes of Manchester United. These aren’t the foundations of future growth. A return to the Single Market is.

* Mark Corner is a UK national, who teaches economic history and philosophy at the University of Leuven, is married to a Czech EU official and lives in Brussels. He has just published A Tale of Two Unions suggesting that Brexit may damage the British Union unless the UK becomes more positive about the way the European Union is structured.