Leaders of Scotland, Wales and Northern Ireland are set to meet in Cardiff on Monday in an unprecedented summit that could intensify calls for greater autonomy and a potential break-up of the United Kingdom.
Scottish First Minister John Swinney, Welsh First Minister Rhun ap Iowerth and Northern Ireland First Minister Michelle O’Neill are expected to discuss a joint approach to constitutional reform, including the right of their respective nations to determine their own futures.
They will be joined by Mary Lou McDonald, president of Sinn Féin and leader of the opposition in the Republic of Ireland. 
The meeting at the St David’s Hotel overlooking Cardiff Bay is expected to focus on four broad areas: the economy, energy, relations with Europe and the wider international community, and self-determination.
The leaders are also expected to endorse a joint declaration asserting the democratic right of Scotland, Wales and Northern Ireland to determine their constitutional futures, potentially including independence referendums.
The gathering comes amid growing pressure for a major overhaul of the UK’s constitutional structure and greater powers for the devolved nations.
‘Status quo is not sustainable’
Swinney, whose Scottish National Party (SNP) has long campaigned for Scottish independence, has described the meeting as evidence of a fundamental shift in the political landscape.
“For the first time ever, Scotland, Wales and Northern Ireland are led by pro-independence first ministers,” he said, arguing that the development showed that the existing constitutional arrangement was becoming unsustainable.
“The momentum behind serious constitutional change is undeniable,” Swinney added.
He has also suggested that Westminster must prepare for a future in which the United Kingdom’s current structure could fundamentally change.
Independence and Irish unity
The summit could give fresh momentum to separate constitutional campaigns across the three nations.
In Scotland, the SNP continues to press for another independence referendum, while Plaid Cymru is seeking greater autonomy for Wales.
Northern Ireland’s Sinn Féin, meanwhile, is campaigning for Irish reunification under the terms of the Good Friday Agreement.
Sinn Féin is expected to use Monday’s meeting to argue that preparations for a referendum on Irish unity should begin now.
A party source said the agreement provided a democratic route for Northern Ireland to determine its future and that Irish unity should no longer be treated as a distant possibility.
Wales demands more powers
For Wales, the talks are also expected to focus on demands for greater control over taxation, public spending, policing and rail infrastructure.
Plaid Cymru is particularly pushing for Wales to receive revenues generated from the Crown Estate, including income from seabed areas used for offshore wind projects, rather than having the money transferred to the UK Treasury.
The party has argued that closer cooperation among the three devolved nations could deliver practical benefits while strengthening their collective bargaining position with Westminster.
Burnham pushes back
The growing constitutional debate has also drawn attention from Andy Burnham, who has previously indicated that another Scottish independence referendum could potentially be considered if there were a clear public consensus.
However, Burnham has since insisted that another referendum is not on the table before the next UK general election.
In a letter to Swinney, he said there was no clear consensus for Scottish independence and no evidence that a majority in Northern Ireland currently wanted to leave the United Kingdom.
Burnham also pointed to Labour’s 2024 election manifesto, which stated that the party did not support Scottish independence or another referendum.
He argued that reopening the issue would distract from the government’s priorities of economic growth and tackling the cost-of-living .
