Nationalist first ministers sign a Cardiff pact on self-determination

John Swinney, Rhun ap Iorwerth, Michelle O'Neill and Mary Lou McDonald signed a memorandum of understanding in Cardiff on Monday stating that Westminster's time is coming to an end. They also wrote that no Westminster government has the right to block democracy. It is the first sitting of the SNP, Plaid Cymru and Sinn Fein leaders as the parties that now hold the first minister posts in Scotland, Wales and Northern Ireland.

Plaid Cymru won the Senedd election in May. That result completed a set that did not exist before: Swinney as First Minister of Scotland, ap Iorwerth as First Minister of Wales, O'Neill as First Minister of Northern Ireland. McDonald, Sinn Fein's president and leader of the opposition in the Irish Dail, joined them. They met as party leaders, not as a formal intergovernmental council. Northern Ireland's deputy First Minister, Emma Little-Pengelly of the Democratic Unionist Party, said O'Neill had not sought agreement or permission to travel or to sign anything as First Minister.

The text is short. It says that for the first time people across these islands have first ministers in Scotland, Wales and the North of Ireland who are all committed to independence from the United Kingdom. It calls on the British government to prepare for, plan and facilitate constitutional change in each jurisdiction. It says the future of the three nations belongs in the European Union.

The three parties do not want the same next step. The SNP wants an independence referendum in this term of the Scottish Parliament. Swinney told the press conference that Andy Burnham would be the last prime minister of the United Kingdom and that polling trends show Scots would vote to leave if given the choice. Plaid Cymru wants more devolved power and the right to call a referendum. Welsh law today has no clear route to an independence poll, though Cardiff can run votes on further devolution, as it did in 2011. Sinn Fein wants a border poll on a united Ireland under the Good Friday Agreement, which already provides for that vote if the Secretary of State judges that a majority in Northern Ireland is likely to back unity.

Donald Trump's weekend remarks in support of Irish unity hung over the room. British and Irish politicians had already spent Sunday arguing about whether a sitting American president should weigh in. The Cardiff text does not mention Trump. It does mention jobs, energy and a stronger voice. Those lines are the working agenda the parties say they can share while their constitutional clocks run at different speeds.

Westminster's reply will decide how much of this is theatre. The UK government can refuse a Scottish referendum, as it has before. It can stall a border poll. It cannot unmake the fact that the three devolved executives are now led by parties that campaign against the Union. That is the change the memorandum keeps repeating.

Swinney called the day a turning point in the constitutional journey of the UK and said there should be no obstacle to each nation choosing its path. Ap Iorwerth, hosting in Cardiff Bay, framed the meeting as a claim to tools rather than a break in culture. We have very close and important relationships, culturally, across these islands that we want to maintain, he said. We are talking here about having the tools to build a future for our people through the right of self-determination.

The three signatures look united on a podium and diverge the moment a ballot paper is designed. A Scottish referendum is a reserved matter. A Welsh independence referendum would need new statute. An Irish border poll is a Secretary of State judgement under a treaty. Those are three legal machines, not one.

What the memorandum does, today, is put a joint sentence on paper that Downing Street now has to answer. The parties have also given themselves a reason to keep meeting on energy and industrial policy, which is the part of the text that can produce work even if no referendum is called this year.

Little-Pengelly's objection is a reminder that Northern Ireland's executive is a two-headed office. O'Neill can sign as a party leader. She cannot commit the Executive without her deputy. That limit is written into the settlement the same way the border poll is. Cardiff did not change it.

The next test is whether Swinney tables a referendum demand in Holyrood this term, whether the Welsh government drafts a devolution vote that inches toward an independence question, and whether the Secretary of State is forced to publish a view on a border poll after Trump's comments. The memorandum itself creates none of those processes. It only says the three parties will push them at the same time.