evidence: Like the rest of the UK, Northern Ireland is no longer part of the EU customs union, the basis for common tariffs on all goods entering the bloc. That means customs checks are necessary. However, to avoid a hard border with the Republic of Ireland, those checks instead take place between Northern Ireland and Great Britain; this, in effect, creates a new border in the Irish Sea. Meanwhile, Northern Ireland—but not the rest of the UK—continues to follow many of the EU’s single-market regulations, allowing the land border with Ireland to remain open. Additionally, the protocol is aided by a separate Ireland-UK agreement that allows free movement of people between the two countries. [...] To break the impasse and address unionist concerns, in early 2023 the EU and the UK government under Prime Minister Rishi Sunak struck a new deal known as the Windsor Framework. It created a "two-lane" system in which goods staying in Northern Ireland are exempted from checks while those destined for Ireland are still required to undergo inspection. It also gives Stormont the ability to veto some EU regulations, among other measures. Unionists nonetheless maintained their opposition for nearly a year, arguing the framework did not go far enough. But the DUP relented after the January 2024 update offered several additional compromises, including further reducing border checks, reaffirming Northern Ireland’s constitutional role in the UK, and earmarking nearly $4 billion in new funding for the revived Stormont government. [...] This BBC explainer delves into the details of the Northern Ireland Protocol and the proposed Windsor Framework.