The Brexit debate does not end with our departure from the EU tonight

Editorial: The prospect of a significant US-UK trade deal being completed within a mere five years seems over-optimistic at best, at worst a folly of magical thinking

British MEPs and their assistants mark the UK’s withdrawal from the EU at the European parliament in Brussels (AP)

When Britain joined the European project in 1973 it was seen as a voyage to an unknown destination. Today, on the day the United Kingdom leaves the European Union, we again embark on an unknown journey.

Although The Independent supported our membership of the EU, we remain optimistic – about the medium term, at any rate. As Hamish McRae, our economics commentator, has said, Britain was always only “half in” the EU; now we will be “half out”. The change in our relationship may not be, therefore, as dramatic as some of the fears inspired by the talk of a hard-break Brexit.

In the short term, however, the risks of leaving the single market remain clear and present. Just because Boris Johnson defied expectations in securing a withdrawal agreement – and a general election to deliver it – does not mean he is guaranteed even the minimal trade deal the country needs by the end of this year.

If we and the EU end up imposing tariffs on each other, the damage to our economy will be severe. Even if this worst scenario is averted, there are enough second order problems yet to be resolved. No one knows, for example, how the arrangements in the withdrawal agreement for Northern Ireland are going to work. The prospect of a significant US-UK trade deal being completed within a mere five years seems over-optimistic at best, at worst a folly of magical thinking.

Depending on the steepness of the next “cliff edge”, at the end of December, there is likely to be a period of economic adjustment. But if there are job losses, they are likely to be cushioned by the remarkable ability of the economy currently to generate employment. Our economic argument against leaving was always a long-term one: not that we will be worse off immediately – although that is possible – but that, over time, we will become less prosperous than we otherwise would.

Our support for a Final Say referendum on EU membership reflected our respect for democracy rather than a campaign for a specific outcome, either in or out. Having lost that argument, however, it must still be possible for those in favour of a pro-European future to help foster an outward-looking, not insular, society. Brexit Britain should not close in on itself.

It is tempting to scoff at the prime minister’s words in the House of Commons this week – “We are going to take this country forward and outward into the world” – and a certain amount of scoffing is democratic and right. But what is important now is holding Mr Johnson to those words and making a common cause of the values of connectedness, rather than isolation.

Mr Johnson’s claim about Brexit “unleashing Britain’s potential” should met be with some scepticism, but that does not mean Britain cannot thrive outside the EU if it retains its status as a liberal, outward-looking nation. It can be done, just as Canada coexists alongside the combined single market to its south.

As is often observed, the Brexit debate does not end tomorrow. There is a year of urgent trade negotiations ahead, and the prospect of continuous renegotiation of our future bonds with that vast economic market on our doorstep. In that dialogue, The Independent will be pressing for a closer relationship. And in that endeavour, we believe we will be working with the grain not just of our national economic interest but of British public opinion.

The decision in 2016 to leave the EU was a narrow one; most recent opinion polls suggest that, by a slim margin, people now think it was the wrong choice. The opportunity to revisit that decision has been rejected, but the pressure of public opinion will nevertheless tend, over the medium term, to keep us as close as possible to the EU. In that debate, The Independent will stand for politics being rooted in truth not misleading election claims, so our readers can continue to trust our reporting, as we hold power to account for delivering a relationship with the EU that is transparent and honest – including, of course, on such controversial subjects as immigration.

The EU will also face disruption, and must decide whether to respond by closer integration between its member states – as Emmanuel Macron, the French president, clearly wants. However, if our EU friends are serious about wanting us back (which was the tenor of much of the debate in the European parliament on Wednesday) they should try to keep the structures of the EU flexible, to allow that to possibility to remain open.

The most hopeful way of looking at leaving is an adjustment, a course correction forced by public opinion at one moment in time, a reaction against centralisation seen as undemocratic. But we should recognise that it will be followed over the years by further adjustments – a voyage that we believe, and hope, will bring us closer to our common European home again.