The British Borders Act only highlights the illogicality of having two jurisdictions on a single island

Ireland’s sizeable population of EU citizens will lose freedom of movement, no matter how long they have lived here.

Particularly affected are people living in the border areas who regularly cross that invisible line to work, shop, socialize or attend sporting events – they must now apply for pre-authorisation unless they are Irish or British citizens.

Tourists in the republic who fancy a spontaneous trip to the Titanic Center or the Giant’s Causeway are also affected – or vice versa for holidaymakers based in Belfast and other parts of the north. Spontaneity is out.

With multiple border crossings, these new arrangements cannot be effectively monitored even if the political will is there – but certainly the main Belfast-Dublin corridor can be targeted.

This new requirement for an ETA, or Electronic Travel Authorization, represents an ongoing attempt to pin abrasions to Ireland’s prized frictionless border.

In short, things have gotten all Brexity again, as if the world doesn’t have enough to cope with.

It is further evidence of how insignificant Irish interests are to the north or south in the Westminster bubble. Because if non-Irish or non-British passport holders are to be checked when crossing the border, then it is obvious that everyone has to face some kind of control.

This is another layer of bureaucracy for shippers with deliveries on both sides of the island and therefore acts as a barrier to trade. And will there be fees associated with this ETA?

The eight DUP MPs, ranging from Jeffrey Donaldson to Sammy Wilson, voted unanimously against a House of Lords amendment to exempt Northern Ireland from legislation – presumably believing they would become ever more closely linked to the UK. Some people never learn.

As for the parties in the Dáil, even those with few common policies have banded together to resist opposition to defining Ireland by its border. Foreign Secretary Simon Coveney was unusually blunt about Britain’s toneless resistance to compromise: “Our concerns in this regard have been clearly communicated but ignored.”

He said the “regrettable” decision went against the free movement of people on the island, which both governments have supported for many years.

Sinn Féin chairwoman Mary Lou McDonald said: “Are we really saying that Poles who live and work in Lifford now need papers to travel to Strabane or from Emyvale to Aughnacloy?

“It will be devastating for the tourism sector, particularly for counties like Donegal and along the border region. This could cost tens of thousands of jobs in an industry that is struggling to bounce back post-Covid-19.”

Michael McGrath, who represented the Taoiseach on Leaders’ Questions, told the Dáil that making a distinction between EU citizens from other Member States and Irish citizens is neither “practical nor fair”. Protests in Dublin and shrugs in London. Buck up folks, the ETA is a simple online form that’s pretty easy to renew once you’ve applied for it.

North Secretary Brandon Lewis (my government intends to break the law “in a specific and limited way”) said: “There will be no controls at the border. UK and Irish citizens can continue to travel freely.

“This new ETA requirement is about protecting the common travel area from abuse.” So controls will take place, but not at the border. But how could they be imposed without controls? Isn’t that a hard limit?

And so the case for unity continues to grow. Here’s another example of why a two-jurisdictional system on a small island is illogical, counterproductive, and hostile to the best interests at large. There is no justification for Tory politicians, aided and abetted by a tiny group of DUP apostles, to usurp the right to change the way people in Ireland legally move around the island.

Others in the UK claim their national security is at risk if controls are not put in place.

Which tells us everything we need to know. This is really about east-west curbs rather than north-south, which are essentially impractical.

The impact of the legislation will be to tighten the sea boundary rather than the permeable land boundary.

The UK sees the common travel areas as open to “abuse”, to quote Mr Lewis. For example, our welcome Ukrainian guests are potentially undesirable – there are currently no obstacles preventing them from crossing the border and relocating from Northern Ireland to the UK.

This is where the new law going through Westminster plays a role as part of a revision of UK immigration laws that includes provisions for asylum seekers.

First and last, the Nationality and Borders Bill is designed to protect Britain. It will either not be policed ​​or a half hearted application will be made on the island of Ireland but good luck trying to enter England, Scotland or Wales without this visa waiver or a British or Irish passport.

Meanwhile, tourism and hospitality will be hit on both sides of the border, but perhaps particularly so in Northern Ireland, as international tourists often enter the region via the Republic.

If vacationers need to apply for an American-style visa waiver in advance, or if there are delays in processing, they may well choose to stay on one side of the border.

If only someone had explained this disadvantage of the DUP quota vote at Westminster. Oh wait, it makes no difference in a world where ideology trumps everything.

But these lawmakers are on their way to discovering another law – that of unintended consequences, as the logic of unity picks up steam.