Of all Brexit's consequences, the one affecting Northern Ireland is the most delicate. The region, six counties that remained in the UK after the partition of the island in 1921, is the only part of the country with a land border with the European Union: 499 kilometres separating Northern Ireland from the Republic of Ireland, crossed by more than two hundred roads. For thirty years, during the Troubles, that border was guarded by soldiers and watchtowers; the 1998 Good Friday Agreement made it invisible. Brexit posed a question that seemed to have no answer: how to leave the single market without rebuilding a border on the island?
The "trilemma"
London wanted three incompatible things: to leave the single market and the customs union, to have no checks at the Irish border and to have no checks between Great Britain and Northern Ireland. It could have two at most. Theresa May proposed the backstop, which would have kept the whole UK in the customs union until another solution was found, but Parliament rejected it. Boris Johnson chose the opposite option: the Protocol on Ireland/Northern Ireland, in force from 2021, kept the region in the single market for goods and moved checks to Northern Ireland's ports, that is, to the Irish Sea.
A border in the sea
The protocol avoided a border on the island but provoked a strong reaction among unionists, who felt separated from the rest of the UK. Goods shipped from Liverpool or Cairnryan to Belfast had to be declared and, in the case of food, certified, as if they were travelling to another country. Some supermarkets struggled to stock their shelves, and in 2021 there was tension and rioting in loyalist areas. In February 2022 the Democratic Unionist Party (DUP) withdrew its first minister from the Stormont government, paralysing local institutions, which under the peace agreement must be shared between unionists and nationalists.
The Windsor Framework
On 27 February 2023 Rishi Sunak and European Commission president Ursula von der Leyen agreed the Windsor Framework, which redesigned the protocol. Goods destined to stay in Northern Ireland travel through a "green lane" with minimal checks; only those at risk of ending up in the Republic go through the "red lane". Supermarket food is labelled Not for EU and can arrive under British rules. The Northern Ireland Assembly also gained the so-called Stormont brake, an emergency mechanism to object to new EU rules. After further assurances from London, the DUP returned to government: on 3 February 2024 Michelle O'Neill of Sinn Féin became the first republican to lead the Northern Ireland executive, with unionist Emma Little-Pengelly as deputy.
The best of both worlds?
An unexpected effect is that Northern Ireland is now the only territory in Europe with free access to both the British market and the EU single market for goods. Some businesses have exploited this position and, according to several analyses, the Northern Irish economy has grown faster than the UK average in recent years. Cross-border trade on the island has increased. In December 2024 the Stormont Assembly voted, by simple majority, to keep the agreement's trade rules in force for another four years.
The unification debate
Brexit has also reopened the constitutional question. At the 2021 census, for the first time, people from a Catholic background slightly outnumbered those from a Protestant background, and Sinn Féin, which favours reunification of the island, has become the largest party in both Belfast and Dublin. The Good Friday Agreement provides that a referendum on Irish unity can be called if a majority in favour appears likely; for now polls indicate that most people in Northern Ireland prefer to remain in the UK, but the margin has narrowed.
For travellers
For visitors nothing changes: there are no checks between Northern Ireland and the Republic, and you cross the border without noticing, often only because road signs switch from miles to kilometres. Mind your documents, though: to enter the UK, and therefore Northern Ireland, EU citizens need an ETA, even when arriving overland from Dublin. See our guide to Northern Ireland, Belfast, the region's history and the Brexit special.