A new UK immigration law means non-Irish citizens of the EU will have to get clearance to cross the border into Northern Ireland.
The measure adds more bureaucracy and even again raises the spectre of a border in Ireland after Brexit.
Brexit passed in the UK in 2016 largely because of fears the country was being burdened by migrants. The big slogan was “Take Back Control”.
The new National and Borders Bill passed in the lower house of the London parliament and is now before the House of Lords.
Efforts by Northern Ireland MPs from SDLP and Alliance, backed by the opposition Labour and Liberal Democrats, to exempt Northern Ireland did not succeed.
It is a big beast of a draft law covering things like tougher penalties for people smuggling. But its main aim is to stem the inflow of migrants.
The problem for Ireland is that non-Irish citizens who come from the EU and the adjoining European Economic Area (EEA) – that’s Norway, Iceland and Liechtenstein – will now have to get the equivalent of a US-style visa waiver.
That means going online, filling in an electronic form, and getting a thing called Electronic Travel Authorisation (ETA).
Irish and British citizens are not concerned because they have free movement under the deal which secured the Common Travel Area which has existed since the 1920s.
But European citizens living in the Republic, who regularly go North for work or business, will have to have their ETA, as will tourists in the Republic who want to go Northern Ireland for a few days.
In practice, like most things relating to that 300-mile stretch between Dundalk and Derry, the short answer is it can only be policed with great difficulty – if at all.
But a bit like lying about the details on your car or house insurance forms, everything is fine until “something happens”.
Say an EU or EEA visitor to Northern Ireland without this electronic form is involved in, or witness to, a traffic accident.
Or, say they are victims of a crime, and/or need healthcare. Then they are open to penalties as well as whatever other woe has befallen them.
It is an extra constraint on cross-border contacts. It also raises the spectre of some form of border controls which were not supposed to happen at all.
Civil rights campaigners also fear this device could become a focus for discrimination against European citizens from different ethnic backgrounds because it justifies identity controls.
That it is a technical thing involving an online form and people will quickly get used to it. Once done it will be easy to renew.
The efforts to take Northern Ireland out of the equation failed because a tabled amendment did not get on the parliamentary agenda.
So far, it has been cautious despite big warnings from the Alliance Party and the SDLP in Northern Ireland. It is understood that – one more time – London had not factored in Northern Ireland and the Border into its planning for this law. But quiet diplomacy will continue.
There still is scope to change the fine print on how this one is implemented.
The London authorities have cited 2025 as an implementation date – so there is also some time to dial this one down.
A spokesperson for the Irish Government said further clarity will be sought from the UK Government on how it is proposed to apply the new requirement for Northern Ireland.
"Tens of thousands of people cross the land border every day.There are also considerations in terms of supply chains and tourism, should this proposed legislation impact on any cross-border movements for EU/EEA citizens,” the spokesperson said.
“The Irish Government has made its position clear that there should be no hard border on the island of Ireland. We know that this legislation remains under consideration within the UK Parliament.
"We will follow up closely with our UK Government counterparts to ensure that our position is clearly heard as this legislation progresses,” the spokesperson added.