CARDIFF — John Swinney, Rhun ap Iorwerth, and Michelle O'Neill signed a memorandum of understanding in Cardiff on Monday. The leaders called on the British government to prepare for, plan, and facilitate constitutional change in each jurisdiction.

This is the first time the leaders of Scotland, Wales, and Northern Ireland are all from parties committed to independence or unification. John Swinney, Rhun ap Iorwerth, and Michelle O'Neill attended the summit in their capacity as party leaders rather than as government officials. Mary Lou McDonald attended the summit in Cardiff.

The memorandum of understanding states: "For people watching across these islands — for people watching around the world — there could be no clearer sign that Westminster’s time is coming to an end." The document further states: "Momentum is behind our movements; we believe that constitutional change is coming." It also asserts: "No Westminster government has the right to block democracy or undermine the principle that our people will decide their own future." The memorandum of understanding states: "The future of our nations belongs in the European Union." The memorandum of understanding commits Plaid Cymru, the SNP, and Sinn Féin to strengthening co-operation in areas including the economy, renewable energy, relations with Europe, and self-determination. The memorandum of understanding states that the parties recognize they have different constitutional positions and that each nation will determine its own future in its own way and in its own time.

Michelle O'Neill stated that for Northern Ireland, the meeting is about the fulfilment of the Good Friday Agreement itself. Michelle O'Neill replied: "I am first minister in the north of Ireland. This is about historic change happening all around us." Nicola McEwen, director of the University of Glasgow Center for Public Policy, said the summit has no legal significance.

Laura McAllister, a professor of public policy at Cardiff University, said the aims and timelines for independence sought by the first ministers are fundamentally different. The U.K. government says the threshold for a Northern Ireland unification referendum has not been met.

A Survation poll found 47% of Scottish voters support independence. A Survation poll put support for independence in Wales at 32%. A University of Liverpool survey found 36% in Northern Ireland would vote for Irish reunification.

The Scottish National Party wants a second independence referendum within the next five years. Plaid Cymru has ruled out an independence referendum in its first term. Mary Lou McDonald said she expected an Irish reunification poll to take place by 2030.

Why It Matters

The signing marks a coordinated political effort by the governing parties of Scotland, Wales, and Northern Ireland to advance constitutional change and re-establish ties with the European Union following the U.K.'s formal departure in January 2020. The memorandum explicitly challenges the authority of the Westminster government to block democratic processes regarding national self-determination, signaling a shift in how these regional leaders approach their relationship with the central U.K. government.

The event shows differing timelines and legal frameworks for potential constitutional changes across the nations. While the Scottish National Party seeks a referendum within five years, Plaid Cymru has ruled one out for its first term, and the U.K. government maintains that the threshold for a Northern Ireland unification vote has not been met under the 1998 Good Friday Agreement.

Timeline

On April 10, 1998, the 1998 Good Friday Agreement requires a vote on unification if polls indicate it would likely pass. On September 18, 2014, voters rejected Scottish independence in a 2014 referendum by 55% to 45%. On January 31, 2020, the U.K. formally left the European Union in January 2020.

On the same day, John Swinney, Rhun ap Iorwerth, and Michelle O'Neill attended the summit in their capacity as party leaders rather than as government officials. The memorandum of understanding states: "Momentum is behind our movements; we believe that constitutional change is coming." The memorandum of understanding states: "No Westminster government has the right to block democracy or undermine the principle that our people will decide their own future."