The first ministers of Wales, Scotland and Northern Ireland will meet in Cardiff on Monday to discuss ways of “working more closely”, including on constitutional issues.
It will be the first face-to-face meeting between the three nationalist leaders since Plaid Cymru’s Rhun ap Iorwerth took office in May.
Ap Iorwerth will host the SNP’s leader John Swinney and Sinn Féin’s Michelle O’Neill on Monday morning. Sinn Féin president Mary Lou McDonald will also attend.
He will hold further talks with Swinney in the afternoon with both men expected to sign an agreement on “future collaboration in areas of shared interest”.
For the first time since devolution began Wales, Scotland and Northern Ireland, all have first ministers who want to leave the United Kingdom.
A Plaid spokesperson said ap Iorwerth’s meeting with Swinney, O’Neill and McDonald was “an opportunity for the leaders of Plaid Cymru, the SNP and Sinn Féin to come together and talk about how we can work more closely on the issues that matter to people across our nations”.
“Following the historic Senedd election in Wales and the changing political landscape across these islands, there is a strong case for practical political cooperation on areas including energy, the economy and our relationship with Europe, as well as on the wider political and constitutional questions facing our nations and on the right to self-determination,” they added.
Swinney believed their was “undeniable” momentum behind constitutional change.
“Every nation across these islands is standing at a moment of incredible constitutional opportunity,” he said.
“There is a growing consensus that the Westminster system simply is not fit for purpose and does not work for ordinary people.
“Prime Minister Andy Burnham has accepted that himself – and the people of Scotland, Wales and Northern Ireland have made it clear at the ballot box.”
The meetings come days after the matter of Scottish independence resurfaced in the Commons.
During Prime Minister’s Questions on Wednesday, Andy Burnham appeared to indicate a second referendum could be held in Scotland if there was clear public support for a vote.
He compared the situation to the conditions for a border poll in Northern Ireland explaining the Good Friday Agreement made clear a border poll would be “considered by the Northern Ireland Secretary when there is a clear consensus in the country, when public opinion has changed to the point where the call has to be considered”.
“I would say that it is exactly the same situation in Scotland,” he added.
The apparent softening in tone was welcomed by Swinney before Burnham clarified that another Scottish referendum remained “off limits”.
A referendum on Scottish independence in September 2014 saw the country vote to remain part of the UK by a margin of 55% to 45%.
