The Northern Ireland Protocol was the part of the 2019 Brexit withdrawal agreement designed to avoid a hard border on the island of Ireland. It kept Northern Ireland aligned with many EU single-market rules for goods, which meant checks on some goods moving from Great Britain to Northern Ireland. Unionists objected that this put a border in the Irish Sea. Within months of it taking effect in January 2021 it became the main source of friction between London, Dublin and Brussels.
Dublin's concerns
Through 2021 the Irish government repeatedly expressed concern about the tone and direction of the UK's approach. Ministers including the then Foreign Affairs Minister, Simon Coveney, warned that threats to suspend parts of the Protocol, or to override it, would damage relations with the EU and with Ireland. In October 2021 Coveney and the UK's Brexit minister, Lord Frost, traded criticism in public on social media. The Irish government also said that relations were being strained by the UK's legacy proposals published that summer.
The UK government's position was that the Protocol was being applied too rigidly, was harming trade and had lost the consent of the unionist community, and that it was entitled to consider using Article 16, the Protocol's safeguard clause.
Escalation and settlement
In June 2022 the UK introduced the Northern Ireland Protocol Bill, which would have allowed ministers to disapply parts of the Protocol unilaterally. The EU responded with legal action. The bill was later dropped. On 27 February 2023 the UK and EU agreed the Windsor Framework, which created separate routes for goods staying in Northern Ireland and goods at risk of entering the EU, and gave the Northern Ireland Assembly a mechanism, the "Stormont brake", to object to some new EU rules.
Why it matters for legacy
British-Irish cooperation has always been central to dealing with the past, from Weston Park in 2001, which led to the Cory investigations, to the joint legacy framework of 2025. The Protocol dispute showed how quickly that cooperation can fray when the two governments disagree in public, and how much it matters when they don't.