Ben Lowry: The complexities of the border are not even close to being resolved

At the same time, the government is making clear that there will be no border at the Irish Sea.

The latter commitment will delight unionists. Sir Jeffrey Donaldson, one of the DUP’s most influential MPs, said on radio on Monday that such a border could “unravel the entire peace process”.

Yet nationalists have for months been talking the other way – that Brexit is a threat to the established peace, and that a hard Brexit with a hard border is particularly so.

Note that Norway (not in the EU) and Sweden (in the EU) have customs posts on about a quarter of their road crossings. Norway, while it is in the single market, is not in the customs union, hence the need for checks.

Given that Britain is likely to leave the customs union, so it can strike its own trade deals, London seems to be optimistic that it can not only avoid such posts, but CCTV too.

This betrays a determination not to upset nationalists. The danger for unionists has always been that if Britain has to upset someone, it will choose them rather than enrage republicans.

Dissident terrorists would of course try to topple CCTV cameras, but even so, you would think that the option of cameras at least should be kept open to maximise the much touted “technological” solutions to border checks.

Norway and Sweden have no immigration border checks but both are in the Schengen passport-free area.

The UK and Republic are both outside it, but have their own internal passport free Common Travel Area, to which London is reaffirming its commitment.

However, if post-Brexit the rights of EU citizens to live in the UK are restricted, and there are no checks on either the land border or at the Irish Sea, then EU nationals will soon realise they can fly into Dublin, show their passport to gain entry, then travel to Great Britain via Northern Ireland without checks.

The border complexities are not even close to being resolved.

• Ben Lowry (@BenLowry2) is News Letter deputy editor