Celtic Leaders Sign Joint Pact Toward Independence Referendums

Rhun ap Iorwerth, John Swinney, Michelle O'Neill and Mary Lou McDonald signed a memorandum of understanding in Cardiff on Monday 14 September 2026 to put the UK's Celtic nations on the path to independence referendums. The Guardian

The memorandum recognised that "the political landscape across these islands is changing". It stated that "Momentum is behind our movements; we believe that constitutional change is coming".

The memorandum stated that "No Westminster government has the right to block democracy or undermine the principle that our people will decide their own future". It called for the British government to prepare for, plan and facilitate constitutional change in each jurisdiction, or separate political area.

The four leaders met in Cardiff in their capacity as party, rather than government, officials. The meeting discussed economic, energy and international cooperation as well as self-determination, the right of people in a place to decide how they are governed.

Polling reported ahead of the summit suggested 47% of Scottish voters would opt for independence in a referendum held tomorrow, with 36% support in Northern Ireland. The Guardian

The broader context here is the choice to act jointly and in party capacity. A memorandum of understanding between party leaders carries political weight, like a public joint promise. It does not carry intergovernmental authority, the legal power used when governments act officially. That format allows coordination across different mandates and constitutional positions while avoiding the constraints on ministers using official machinery.

Looking at what this means for Westminster, the memorandum frames the question around process and permission. It asserts that decisions belong to people in each jurisdiction. It asks the British government to plan for and facilitate change. That demand is broad. Preparation and facilitation can mean very different things in law and practice, from setting criteria for referendums to defining the role of Parliament, the devolved legislatures and the courts. The text does not resolve those differences. It consolidates pressure for London to address them.

In my view, the inclusion of economic, energy and international cooperation alongside self-determination deserves close attention. Referendum movements often focus on legitimacy and timing. Governing agendas signal capacity, or ability to run a state. By linking constitutional claims to practical policy, the leaders show how they want cooperation to work before any vote and how separate states might interact after one. That linkage will invite scrutiny. Voters will ask about costs, trade-offs and institutional readiness. Other governments will ask about continuity and reliability.

For context on the polls, the starting points are uneven. A 47% share in Scotland describes a competitive contest. A 36% share in Northern Ireland describes a longer trajectory. The memorandum treats both as shared momentum. Each place still has its own electorate, party system and legal route to a referendum. Joint declarations do not harmonise those routes. They create a shared narrative that each movement must still test at home.

What may come next turns on response and sequencing. London can ignore, rebut or engage on the request to prepare. The signatories can deepen joint policy work or move toward separate timetables. Neither course guarantees a referendum. The Cardiff text sets a public baseline: change presented as coming, democratic consent as determinative, and obstruction as illegitimate. Whether that baseline alters behaviour in Westminster, in the devolved institutions and among voters will depend on elections, legislation and litigation still to unfold.