According to Experts.news, the leaders of the ruling nationalist parties in Scotland, Wales and Northern Ireland signed a memorandum of cooperation in Cardiff on 14 September, which enshrines the right of their peoples to determine their own constitutional future and calls on the UK government to prepare for possible constitutional changes.
The document was signed by John Swinney, leader of the Scottish National Party (SNP) and First Minister of Scotland, the leader of Plaid Cymru and First Minister of Wales, Rhon ap Yorwerth, and the Vice-President of Sinn Féin and First Minister of Northern Ireland, Michelle O’Neill. Sinn Féin President Mary Lou McDonald also attended the meeting.
However, the participants spoke in their capacity as party leaders, rather than on behalf of the governments of Scotland, Wales and Northern Ireland. This is particularly important in the case of Northern Ireland, where power is shared between Sinn Féin and the Democratic Unionist Party (DUP). Deputy First Minister Emma Little-Pengelly of the DUP stated that O’Neill does not have the authority to sign such documents on behalf of the Northern Ireland government.
The memorandum’s key political provision was a call on the UK government to “prepare for, plan and facilitate constitutional changes in Wales, Scotland and Northern Ireland”. The parties also reaffirmed the right of each of the three nations to determine their own future through democratic means.
However, the wording of the memorandum, as published by the British media, does not contain the expected tougher demand for immediate referendums on secession from the United Kingdom. The focus is primarily on recognising the principle of self-determination, establishing mechanisms for future constitutional changes, and London’s commitment not to block a democratic choice should sufficient support emerge within the regions themselves.
Sweeney said that the UK is at a “turning point in constitutional change” and that the people of each of the three territories should be able to determine their own future. Earlier, on 10 September, he wrote to the UK Prime Minister, Andy Burnham, proposing the creation of a legal mechanism that would allow a new referendum on Scottish independence to be held should there be a sufficient public mandate.
On 28 August, the Scottish Government published a draft of a new Referendum Bill containing the same question used in 2014: ‘Should Scotland be an independent country?’. The bill is due to be introduced into Parliament once the necessary powers have been granted by Westminster.
In Northern Ireland, the legal situation is different. The possibility of holding a vote on unification with Ireland is already provided for in the 1998 Belfast Agreement. The decision to hold such a referendum is taken by the UK Secretary of State for Northern Ireland if they consider it likely that a majority of the population would support unification.
In Wales, there is no permanent legal mechanism in place for holding a referendum on independence. That said, the current Plaid Cymru government regards independence as its ultimate goal, although Rhôn ap Iorwerth emphasises that there is as yet no specific timetable for such a vote and that the decision must depend on the views of the people of Wales themselves.
In addition to constitutional issues, the participants in the meeting agreed to expand cooperation in the economy, energy, relations with the European Union and international politics. Nationalist parties believe that, following Brexit and changes to the political balance within the UK, Scotland, Wales and Northern Ireland now share more common interests in their relations with London.
The summit was the first such event since the 2026 elections, when nationalist and pro-self-determination parties simultaneously took the helm of the governments of Scotland, Wales and Northern Ireland. However, the signed document does not yet have legal force and does not automatically trigger any referendums.