Leaders of nationalist parties from Scotland, Wales, and Northern Ireland have signed a memorandum of understanding pledging mutual support for their respective independence movements, signaling a coordinated push to dismantle the United Kingdom. The agreement was signed during a meeting in Cardiff on September 14, 2026, involving Scottish National Party (SNP) leader and Scottish First Minister John Swinney, Plaid Cymru leader and Welsh First Minister Rhun ap Iorwerth, Sinn Fein president Mary Lou McDonald, and Northern Ireland First Minister Michelle O’Neill.

The memorandum commits the parties to collaborate on areas including the economy, energy, international relations, and support for the right of each nation to determine its own future. It asserts that the political landscape across the UK is shifting and states, “Westminster’s time is coming to an end.” The agreement also emphasizes a shared vision for their nations to rejoin or remain part of the European Union, rejecting what is described as the “broken economic model” imposed from Whitehall.

John Swinney described the gathering as a pivotal event, proclaiming that Andy Burnham would be the last UK prime minister. He called for a fresh independence referendum within five years for Scotland and insisted there should be no obstacles to the peoples of Scotland, Wales, and Northern Ireland deciding their own futures. Rhun ap Iorwerth indicated that the timing of a Welsh independence referendum would depend on public support, which he said appears to be growing based on polling data. Mary Lou McDonald characterized the meeting as “historic” and emphasized the assertion of an “inalienable right” for the nations to choose their direction.

Michelle O’Neill highlighted the ongoing significance of the Irish unity debate in light of statements from former US President Donald Trump, who on a recent visit to Ireland described reunification as “one of the naturals of all time.” O’Neill suggested Trump’s remarks underscore that aspirations for a united Ireland remain alive and central to Sinn Fein’s goals. However, her participation in the summit drew criticism from pro-union politicians, including Emma Little-Pengelly of the Democratic Unionist Party, who challenged O’Neill’s authority to represent the office of First Minister in this context.

The announcement prompted responses from unionist and Conservative figures. Harriet Cross, a Conservative spokesperson for Scotland, condemned the pact as a distraction from pressing issues like education and the economy, and criticized the inclusion of Sinn Fein's leadership due to the party’s historic associations with the Troubles. Andy Burnham’s office reiterated his firm support for the Union and his priority on delivering domestic policy improvements across all four nations, distancing the government from constitutional debates.

While the memorandum marks a symbolic step toward cooperation among nationalist forces, some analysts have questioned its practical impact, noting that no concrete roadmap for independence or Irish reunification was included. Legal frameworks in the Republic of Ireland and the UK, such as the Good Friday Agreement, provide a clear pathway for Northern Ireland’s unity referendum, but any such votes in Scotland and Wales require approval from the UK government. Following recent elections, the SNP narrowly missed an outright majority at Holyrood, with the party arguing that support from the Scottish Greens constitutes a pro-independence majority sufficient to push for a referendum, a stance not accepted by Downing Street.

Despite these divisions, the memorandum represents the most explicit collective commitment from the devolved nationalist parties to date, reaffirming their shared objective of constitutional change and greater autonomy from Westminster.