The United Kingdom (UK) was a member of the European Union (EU) from 1973. In a referendum held on 23 June 2016, the people of the UK voted to leave the EU. One of the reasons was their unhappiness with the fact that immigrants from EU member states could move freely and take up jobs in other EU member countries, including the UK. Conservative Party politicians also promised that the UK’s “national sovereignty” would be restored by leaving the EU. The vote was 17.4 million in favour of leaving while 16.1 million voted to remain.

Long and difficult negotiations followed to exit from the EU and then to negotiate a new free trade agreement (FTA) between the EU and the UK. After Brexit the UK is no longer part of the customs union and the single market with the EU. The new FTA allows for duty-free quota-free trade in goods traded between the UK and the EU that comply with the applicable rules of origin.

The post-Brexit legal arrangement contained a special deal for trade between Northern Ireland (which is part of the UK) and the Republic of Ireland (which is an independent member of the EU). The EU insisted on protecting the integrity of the EU, and therefore controlling goods from the UK when they enter the EU market. It meant border controls at the border between Northern Ireland (NI) and the Republic of Ireland (ROI). And that was problematic.

A land border between NI and the ROI would have undermined the Good Friday Agreement, which was signed in 1998 and is credited for maintaining peace in Ireland. During the Brexit negotiations it was agreed that the Good Friday Agreement (also known as the Belfast Agreement) had to be preserved. But this prompted difficult discussions about how to manage trade in a post-Brexit Northern Ireland. The Northern Ireland Protocol was therefore concluded. It had to avoid a hard border between NI and the ROI, ensure the integrity of the EU’s single market for goods, facilitate unfettered access for NI goods to the GB market, and include NI goods in free trade agreements between the UK and third countries.

Unionist parties in Northern Ireland, including the Democratic Unionist Party (DUP) strongly opposed this arrangement and refused to particate in the Northern Ireland legislature, forcing a stalemate in NI governance. They argued that the protocol effectively created a border between NI and the rest of the UK, thereby making them second-class citizens compared to people in England, Scotland, and Wales. The DUP also wanted to end jurisdiction for the European Court of Justice (ECJ) over trade matters in NI. The ECJ remains the ultimate arbiter of EU laws.

The Windsor Framework replaces the Northern Ireland Protocol. It is a new post-Brexit trading deal, designed to remove the need for checks on goods travelling between NI and the rest of the UK. It was announced on 27 February 2023. The agreement also creates a ”Stormont brake”, under which 30 members of the Northern Ireland Assembly, from at least two parties, can ask the UK to veto changes in EU single-market rules.

The NI Protocol effectively establishes a sea border between the mainland and the island of Ireland. The Windsor Framework sets out a two-tier customs system that sees goods remaining in the UK (heading to NI) in a ‘green lane’ that avoids customs checks; while subjecting goods bound for the ROI to the ‘red lane’ for customs.

The Windsor Framework was entered into between Prime Minister Sunak and EU Commission President Ursula von der Leyen. It follows months of discussions between the UK and EU. Following their meeting, Sunak and von der Leyen announced that they have now agreed how to iron out many of the issues with the previous deal, which caused friction between the EU and the UK. It was never going to be easy to divorce from the EU; the peculiarities of relations in Ireland made matters more complicated.

It will take time for this new deal to become operational. The UK Prime Minister hopes that the two-lane border system and greater say over which EU trade rules to follow, will be enough to win over the Unionists. We will have to wait and see whether this happens; and brings the controversy around the Northern Ireland Protocol (and tensions between London and Brussels) to an end.