Sinn Féin, SNP and Plaid Cymru Unite

Three Nations Push for Constitutional Change Beyond Westminster

Northern Ireland political leaders gathered at Stormont in Belfast on September 14, 2026, as the Northern Ireland Assembly resumed its plenary session. Photo credit: Liam McBurney

Leaders of pro-independence parties in Ireland, Scotland, and Wales met in Cardiff on Monday to sign a memorandum of understanding laying out a plan for strengthened cooperation. The document commits Sinn Féin, the Scottish National Party (SNP), and Plaid Cymru to deepen exchanges on renewable energy, economic policy, and, notably, “supporting the right of each nation to determine its own future.”

“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,” the memorandum 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 agreement includes commitments to break with the economic policy shaped in London and to build a different approach that would “create good jobs, tackle inequality and ensure that wealth and opportunity are spread more fairly.” It also outlines an energy strategy promising to leverage the three regions’ renewable resources to bring more affordable energy to communities.

However, the provision that has attracted the most attention is the commitment to realise the three nations’ right to self-determination. “We call for the British Government to prepare for, plan and facilitate constitutional change in each jurisdiction,” the party leaders wrote. “No Westminster government has the right to block democracy or undermine the principle that our people will decide their own future,” they added.

The meeting followed comments by British Prime Minister Andy Burnham on the possibility of independence referendums in Scotland and Ireland. Burnham ruled out—in different terms—such public votes, drawing criticism from independence-oriented parties.

In Ireland, his remarks were called out for contradicting Good Friday Agreement provisions that foresee a path to the island’s unity. “It is not an option that the British government can choose whether or not to exercise based on what is politically convenient, but a legal obligation that plays a critical role in underpinning the relative peace achieved since 1998,” the Workers’ Party of Ireland wrote.

The SNP insisted their ongoing efforts for achieving independence must be contextualised as a response to the aftermath of the 2014 referendum, where unionist parties argued that staying in the UK provided more stability and predictability. Following that vote—where a majority of Scots opted for remaining in the UK—British authorities failed to live up to such arguments, the party said, including when it comes to the protection of public services. “Westminster blocked legislation designed to protect the NHS from being opened up to US healthcare corporations in post-Brexit trade deals, treating our public health service like a garage sale item,” the SNP wrote.

Pro-union critics suggested the memorandum’s commitments risk diverting public attention from everyday issues toward lengthy constitutional discussions. However, Sinn Féin, the SNP and Plaid Cymru contrasted this with a different approach, insisting that independence would allow more space for challenging harmful policies imposed by the British government and for realising a different vision of society.