Scotland, Wales and Northern Ireland independence campaigns gained fresh momentum on Monday after the leaders of three nationalist parties signed an agreement in Cardiff affirming their commitment to self-determination and constitutional change.
The agreement brings together Scotland’s Scottish National Party, Wales’ Plaid Cymru and Sinn Féin, which seeks Irish reunification in Northern Ireland. The parties said they would work more closely while pressing the UK Government to recognise the right of their nations to determine their constitutional futures. (ITVX)
However, the pact does not mean any of the three nations is about to leave the United Kingdom. Each faces different political and legal routes towards constitutional change.
The development is nevertheless significant because it marks the first time nationalist leaders governing Scotland, Wales and Northern Ireland have formally joined forces around a shared commitment to self-determination.
Nationalist leaders sign Cardiff agreement
Scottish First Minister John Swinney, Welsh First Minister Rhun ap Iorwerth and Northern Ireland First Minister Michelle O’Neill met in Cardiff alongside Sinn Féin president Mary Lou McDonald.
The parties signed a memorandum of understanding declaring that their nations should have the right to decide their own futures through democratic means.
The agreement also calls for greater cooperation on economic policy, energy and international affairs. The parties said constitutional change should be prepared for and facilitated rather than blocked by Westminster. (Holyrood Website)
The leaders attended the meeting as party representatives rather than acting collectively as their respective devolved governments. That distinction is particularly important in Northern Ireland, where power-sharing arrangements require broader political agreement. (TheJournal.ie)
The memorandum said the political landscape across the islands was changing and argued that Westminster’s influence over the constitutional future of the three nations should not override democratic choices.
Three nations, three different constitutional questions
Although the parties share a commitment to self-determination, Scotland, Wales and Northern Ireland are pursuing different political objectives.
In Scotland, the SNP wants another referendum on independence. Scotland held its first independence referendum in 2014, when voters chose to remain in the United Kingdom by 55 per cent to 45 per cent.
The current UK Government has said it does not support another Scottish independence referendum. In a parliamentary response published on 10 September, the Scotland Office said the government had been elected on a commitment not to support independence or another referendum. (UK Parliament)
The Scottish Government, however, maintains that the people of Scotland should decide their constitutional future and argues that a democratic mandate should lead to negotiations with Westminster over a referendum. (Scottish Government)
Wales presents another challenge.
Plaid Cymru supports independence and wants the authority to determine the timing and process of any referendum transferred to Wales. However, the House of Commons Library says this would require changes to the Government of Wales Act and approval through the UK’s constitutional process. (House of Commons Library)
Northern Ireland’s situation is different again.
Sinn Féin seeks Irish reunification rather than the creation of a separate independent state. The Good Friday Agreement and the Northern Ireland Act provide a legal mechanism for a referendum on Irish unity, commonly called a border poll.
The UK Government has repeatedly said there is currently no clear basis to conclude that a majority in Northern Ireland wants to leave the United Kingdom. The decision to call a border poll rests with the Northern Ireland Secretary. (UK Parliament)
Westminster faces renewed constitutional pressure
The Cardiff agreement comes as debates over the future of the United Kingdom have returned to the centre of British politics.
Swinney has continued to press for another Scottish independence referendum, while Plaid Cymru’s victory in Wales’ recent devolved election has given the independence movement a stronger political platform.
In Northern Ireland, Sinn Féin remains committed to a referendum on Irish reunification.
The three movements do not share identical constitutional circumstances. Their agreement, therefore, represents political cooperation rather than a single legal plan for breaking up the United Kingdom.
Recent polling also shows that support for constitutional change remains contested. A Guardian report published before the Cardiff meeting cited varying levels of support for independence in Scotland and Wales and Irish unity in Northern Ireland. Such figures differ between polling companies and questions, meaning they cannot be treated as definitive evidence of a settled public majority. (The Guardian)
The latest agreement is also likely to face resistance from unionist parties and the UK Government.
Northern Ireland’s Deputy First Minister, Emma Little-Pengelly, criticised O’Neill’s participation and said she had not authorised the Sinn Féin leader to represent the office of First Minister at the meeting. (TheJournal.ie)
Independence debate gains a new political alliance
The Cardiff meeting does not create an immediate path for Scotland, Wales or Northern Ireland to leave the UK.
No referendum has been scheduled, and the UK Government has not agreed to new votes in Scotland or Wales.
Northern Ireland already has a legal framework for a border poll, but the government says the conditions for one have not been met. (UK Parliament)
What has changed is the level of political coordination.
For the first time, three nationalist parties leading devolved administrations have publicly joined forces to argue that the future of their nations should ultimately rest with their people.
Whether that political alliance produces new referendums remains uncertain.
For now, the Cardiff agreement has placed the question of the United Kingdom’s future firmly back on the political agenda.