The group met in their capacity as party leaders – rather than as officials in their respective governments.
The leaders of the SNP, Plaid Cymru and Sinn Féin have declared that “Westminster’s time is coming to an end” in a joint agreement aimed at putting pressure on Downing Street to hold referendums on independence.
The first ministers of the UK’s three devolved nations – SNP leader John Swinney, Plaid Cymru leader Rhun ap Iorwerth and Sinn Féin vice president Michelle O’Neill – signed the memorandum of understanding during a meeting in Cardiff on Monday morning.
Along with Sinn Féin president Mary Lou McDonald, who is the leader of the opposition in the Irish Dáil, the leaders called on the Government to “prepare for, plan and facilitate constitutional change”.
The group, who met in their capacity as party leaders – rather than as officials in their respective governments, also stated their ambitions for partnership around the economy, energy and international co-operation.
Great to be in Cardiff to meet with colleagues in Plaid Cymru and Sinn Féin.
Our parties share the belief that the people of our respective nations must be able to shape their own future.
At this pivotal moment of constitutional change, we will deepen our partnership.
— John Swinney (@JohnSwinney) September 14, 2026
The agreement says: “The political landscape across these islands is changing.
“For the first time ever, people across these islands have first ministers in Scotland, in Wales and in the North of Ireland who are all committed to independence from the United Kingdom.
“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.
“We believe there is a better way: nations working together as equals, sharing ideas and expertise, and building relationships based on mutual respect and common interests.
“Momentum is behind our movements; we believe that constitutional change is coming.
“We therefore commit to strengthening cooperation between our parties and identifying practical areas where working together can make a real difference.”
Today, Plaid Cymru, @theSNP and @sinnfeinireland are coming together to reaffirm our commitment to work together in the shared interests of our people 🤝 pic.twitter.com/pyE6J7jxBB
— Plaid Cymru 🏴 (@Plaid_Cymru) September 14, 2026
The agreement sets out plans to “reject Whitehall’s broken economic model” and share ideas on economic growth, expand energy resources, and states that “the future of our nations belongs in the European Union”.
The leaders add: “Our nations have the right to self-determination. No Westminster government has the right to block democracy or undermine the principle that our people will decide their own future.
“We recognise that our parties have different constitutional positions and that each nation will determine its own future in its own way and in its own time.
“We call for the British Government to prepare for, plan and facilitate constitutional change in each jurisdiction.”
