Celtic nationalist leaders sign joint memorandum seeking UK constitutional change

A coordinated declaration in Cardiff

Party leaders from Scotland, Wales and Northern Ireland signed a memorandum in Cardiff on September 14 calling on the British government to prepare for and facilitate constitutional change. The meeting brought together SNP leader John Swinney, Plaid Cymru leader Rhun ap Iorwerth, Sinn Féin vice-president Michelle O'Neill and Sinn Féin president Mary Lou McDonald. The Guardian reported that they acted as party leaders rather than formally on behalf of their devolved governments.

The memorandum says the political landscape across Britain and Ireland is changing and asserts that voters in each jurisdiction should determine their constitutional future. Its significance lies in coordination: separatist parties now lead the devolved administrations in Scotland, Wales and Northern Ireland, and they agreed to cooperate on self-determination alongside economic, energy and international issues. The document itself does not schedule a referendum, alter constitutional law or bind the UK government.

The participants' objectives remain materially different. The SNP wants a second Scottish independence referendum within five years. McDonald said she expected a vote on Irish reunification by 2030. Plaid Cymru has ruled out an independence referendum during its first term and is currently pressing for fuller devolved powers. Northern Ireland also has a distinct legal framework under which its constitutional status depends on majority consent, unlike the arrangements governing possible Scottish or Welsh independence.

Westminster retains the immediate legal power

The UK government's official devolution framework describes powers for Scotland, Wales and Northern Ireland as statutory grants from the UK Parliament and government. Its intergovernmental system provides standing structures for cooperation among the four administrations, but it does not give devolved leaders a unilateral route to secession. The Guardian reported that Prime Minister Andy Burnham's government responded by emphasising household finances and economic security rather than further constitutional referendums.

The next consequential step is political rather than automatic. Burnham is expected to meet the three first ministers in October, when demands for expanded powers may prove more immediately negotiable than independence votes. Observers should distinguish joint campaigning from a common constitutional process: Scotland, Wales and Northern Ireland have different public-opinion levels, institutions and legal pathways. The Cardiff memorandum raises coordinated pressure on Westminster, but any binding change still requires separate democratic and legislative decisions.