The leaders of the ruling nationalist parties of Scotland, Wales and Northern Ireland signed a memorandum of cooperation on September 14 in Cardiff, 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 the leader of the Scottish National Party (SNP) and the First Minister of Scotland John Swinney, the leader of Plaid Cymru and the First Minister of Wales Run up Iorwerth, as well as Sinn Féin Vice-President and First Minister of Northern Ireland, Michelle O'Neill. The meeting was also attended by Sinn Féin president Mary Lou MacDonald.
At the same time, the meeting participants spoke as their party leaders and not 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 said that O'Neill did not have the authority to sign such documents on behalf of the Northern Ireland government.
The main political formula of the memorandum was a call on the British government to "prepare, plan and promote constitutional changes in Wales, Scotland and Northern Ireland". The parties also confirmed the right of each of the three nations to determine their future democratically.
At the same time, the expected tougher demand for immediate referendums on leaving Great Britain is not included in the wording of the memorandum published by the British media. It is primarily about the recognition of the principle of self-determination, the creation of mechanisms for future constitutional changes and the refusal of London to block a democratic choice if the relevant support is formed in the regions themselves.
Swinney said that Great Britain is at a "tipping point of constitutional change" and that the residents of each of the three territories should be able to determine their own future. Earlier, on September 10, he appealed to the Prime Minister of Great Britain, Andy Burnham, with a proposal to create a legal mechanism that would allow a new referendum on Scottish independence if there is a corresponding public mandate.
On August 28, the Scottish government published a draft of a new referendum law with the same question that was used in 2014: "Should Scotland be an independent country?". The draft law is planned to be submitted to the parliament after receiving the necessary powers from Westminster.
The situation is legally different in Northern Ireland. The possibility of holding a vote on unification with Ireland is already provided for in the Belfast Agreement of 1998. The decision on the appointment of such a referendum is made by the British Minister for Northern Ireland, if he considers it likely that the majority of residents will support unification.
There is no permanent legal mechanism for holding a referendum on independence in Wales. At the same time, the current government of Plaid Cymru considers the independence of the country to be the ultimate goal, although Run ap Iorvert emphasizes that there are no concrete terms for such a vote yet and the decision should depend on the position of the residents of Wales themselves.
In addition to constitutional issues, the meeting participants agreed to expand cooperation in the economy, energy, relations with the European Union and international politics. Nationalist parties believe that after Brexit and changes in the political balance within the UK, Scotland, Wales and Northern Ireland have more common interests in relations with London.
The summit was the first such event since the 2026 election, when nationalist and self-determination parties simultaneously led the governments of Scotland, Wales and Northern Ireland. However, the signed document does not yet have legal force and does not automatically trigger any referendum.
