Daniel Hannan is an MEP for South-East England, and a journalist, author and broadcaster.

I’m forever being asked whether I have any regrets or worries about Brexit. Regrets? None: Britain is on the way to becoming a freer, wealthier and more global nation. Worries? Only one: we could, if we mess things up, prejudice relations with our closest neighbour, Ireland. It is, though, a wholly avoidable problem.

I spent a fair bit of time in Northern Ireland during the campaign. The warm-up artist before one Belfast TV debate was a popular local drag act called May McFettridge (the alter ego of John Linehan). “Which o’ yez is fer Leave?” she asked the audience. The Leavers duly cheered. “Aye,” she muttered. “Pradestants!”

Tribal politics, which had been fading in Northern Ireland, made something of a comeback in the run-up to 23 June. I noticed audiences self-segregating frostily on more than one occasion. Being of Scottish Presbyterian origin on one side and Ulster Catholic on the other, I’m perhaps more alert to sectarianism than most English people, and I’ve always loathed it.

One of the happiest developments of the past decade has been the return to normal politics in Norn Iron. Relations between London and Dublin have never been warmer, and the question of territorial change suddenly looks terribly twentieth-century. In the last major survey before the referendum, only 13 per cent of Ulster Catholics, five per cent of the total population, wanted immediate moves toward a united Ireland.

It’s not hard to see why. The border has, to all intents and purposes, disappeared. If I were to summarise the concerns of Nationalist and Republican Remainers in a single sentence, it would be something like this: “We could end up with a hard border again because of how England voted”.

In fact, there is no reason whatever to reinstate a land frontier. No political party in London or Dublin is proposing such a thing. With a modicum of common sense, the present arrangements can be maintained.

A Common Travel Area has existed throughout the British Isles since 1923. It includes the UK and the Republic of Ireland, which are in the EU, as well as the Channel Islands and the Isle of Man, which are not.

Borders regulate the movement of two things: people and goods. Let us consider them in turn. A commonly voiced concern is that, when Britain leaves the EU, it will have to impose border checks in Ireland to stop a flow of EU national across the frontier. After all, the argument goes, a Pole could move perfectly legally from Gdansk to Dublin, then drive across to Newry, and then move to Great Britain.

Well, yes he could. Alternatively he could just fly directly from Gdansk to Luton. The fear of people crossing the land border into the UK is based on a misunderstanding of how our immigration policy works. We won’t require visas from EU nationals after we leave, any more than we require them today from Barbadians, Tunisians, Armenians or Senegalese.

Our immigration policy is based, not on turning people back at borders, but on knowing that they are in the country. Those who enter legally but linger illegally are unable to apply for a National Insurance number and, if they are picked up by the authorities for any reason – a driving offence, say – face deportation.

The only thing necessary to keep the current system in place is for Ireland and the UK to agree, as part of the Common Travel Area, to share all data on who has entered their territories. If a passport swiped at Rosslare or Shannon is logged in the same way as one swiped at Portsmouth or Stansted – something that was on the agenda even before the referendum – there is no need to check documentation at the land border.

So much for people; what of goods? Here, the pressure for controls is likely to come from the Irish – or, rather, the EU – side. We can fairly assume that, outside the EU, the UK will have lower tariffs than now. So why wouldn’t, say, an Australian wine producer ship a consignment to Belfast, drive it across the border, and then reship it from Cork to mainland Europe, thus avoiding the EU’s 32 per cent duty on New World wines?

Again, in theory, he could – though it’s hard to see how it would be worth the expense or the risk. But it would be extremely difficult. Goods are generally moved in bulk in freight ships, with an electronic trail to show where they originated. This is not the 19th century, where moustachioed border guards in epaulettes open every bag. We rely instead on occasional spot checks to see that the reality matches the electronic trail.

If Britain were to agree a free-trade deal with the EU, it would find itself in a similar situation to, say, Switzerland. Lorries may legally be stopped on the Swiss frontier by officials on either side, their manifests may be checked and, if there is reason to be suspicious, their contents may be inspected. In general, though, there is an assumption that, since there are no tariffs between the EU and the Helvetic Confederation, goods should pass freely.

Even if the Republic of Ireland wanted to check every consignment crossing by land from Northern Ireland – which it emphatically doesn’t – the task would be impossible. The Irish border is criss-crossed by a latticework of lanes, many of them dating back to public works projects initiated to offer income to local people during the monstrous famine of the 1840s. Even during the height of the Troubles in the 1970s, it was never feasible to man checkpoints along the entire frontier.

In other words, Ireland would find the imposition of a land border impracticable as well as unpalatable. So what could it do instead? One option would be to carry out any checks when goods were loaded in the Republic for transport by sea to the rest of the EU. Another would be for the UK, on leaving the EU, to opt out of the Common External Tariff, but to retain the aspects of the customs union that pertain to veterinary checks, anti-counterfeiting measures and the like. Again, the electronic paper trail makes it possible to have different tariff rates without having to stop at every border.

All that is needed is the political will, in London and Dublin, to sustain our current partnership. And that will, I’m glad to say, is as strong as it has ever been.