Devolved leaders of Scotland, Wales, and Northern Ireland to sign joint independence pact in Cardiff

The Cardiff summit agenda

The leaders of the devolved governments in Scotland, Wales, and Northern Ireland will meet on Monday, 14 September 2026, to sign a joint memorandum of understanding demanding powers to hold independence referendums. The summit will take place at the St David's Hotel in Cardiff, hosted by Welsh First Minister Rhun ap Iorwerth. Scottish First Minister John Swinney and Northern Ireland First Minister Michelle O'Neill will attend, joined by Sinn Féin President Mary Lou McDonald, who leads the opposition in the Republic of Ireland.

The leaders will convene in their capacity as party heads rather than government officials, representing the Scottish National Party (SNP), Plaid Cymru, and Sinn Féin. The draft agreement is structured around four policy areas: self-determination, the economy, energy, and relations with the European Union. Under the proposal, the leaders will advocate for an exit from the United Kingdom, proposing that Scotland and Wales join the EU as independent member states while Northern Ireland rejoins through Irish reunification. A joint press conference is scheduled to follow the discussions.

Political alignment across devolved nations

The Cardiff meeting follows recent electoral shifts across the three nations, placing pro-independence administrations in power simultaneously. Plaid Cymru formed the Welsh government after winning a plurality in the Senedd in May 2026, ending decades of Labour control in Cardiff. In Northern Ireland, Sinn Féin won the largest share of votes in the 2022 assembly elections, leading to O'Neill taking office as First Minister in 2024 after a power-sharing boycott ended.

Swinney released a statement ahead of the summit asserting that Westminster must adjust to the constitutional demands of the devolved parliaments.

For the first time in history, Scotland, Wales and Northern Ireland are led by pro-independence first ministers. There could not be a clearer sign that the status quo is not sustainable and that Westminster must prepare for a post-UK future.

Westminster response and funding disputes

The summit aims to increase pressure on UK Prime Minister Andy Burnham, who addressed the issue of constitutional votes in the House of Commons earlier in the week. Burnham suggested that a Scottish independence vote could be permitted if a clear consensus emerged, drawing a comparison to the provisions of the 1998 Good Friday Agreement in Northern Ireland. Downing Street subsequently sent a letter to Swinney clarifying that an independence referendum remains off limits.

During an interview on BBC television, ap Iorwerth explained that the leaders share common objectives regarding fiscal devolution and central government relations.

It could be around the constitutional question, it could, more acutely, be around fair funding, making sure resource is shared in a way that is equitable, that feels fair, that we have the powers to build the future for the people that we represent.

International commentary and diplomatic context

The Cardiff gathering also follows remarks made by US President Donald Trump during an official visit to Dublin on Saturday, 12 September 2026. Trump expressed support for the reunification of Ireland, stating that the merger of Northern Ireland with the Republic would be magnificent and would happen sooner or later. His comments drew criticism from opposition parties in the United Kingdom.

The meeting in Cardiff represents the first coordinated joint initiative among the three nationalist ruling parties to formally challenge the constitutional structure of the United Kingdom.