The first ministers of Scotland, Wales and Northern Ireland signed a memorandum in Cardiff on 14 September 2026 calling on "the British Government to prepare for, plan and facilitate constitutional change in each jurisdiction". Downing Street rejected it within hours. The question at its heart, of who decides a territory's constitutional future, is one the Cayman Islands and the other Overseas Territories have raised with London before, in a different form.

John Swinney, SNP leader and First Minister of Scotland, said the moment meant Andy Burnham MP, the UK Prime Minister, would be "the last Prime Minister of the United Kingdom". It is the first time since devolution began in 1999 that all three devolved administrations have been led by figures committed to independence from the UK.

Cayman is not a devolved nation. It is one of 14 UK Overseas Territories, a separate constitutional category that includes Bermuda, the British Virgin Islands and 11 others, whose relationship with the UK is handled through the Foreign, Commonwealth and Development Office rather than through the devolution settlements now under strain in Cardiff and Westminster. But the principle the memorandum asserts, that a nation's own people rather than Westminster should decide its constitutional path, is one Cayman's governments have invoked too.

Swinney signed alongside Rhun ap Iorwerth, First Minister of Wales and Plaid Cymru leader, and Michelle O'Neill, First Minister of Northern Ireland and Sinn Féin vice-president. Sinn Féin president Mary Lou McDonald signed as a fourth signatory. The three parties said the leaders attended as party leaders rather than as members of their governments. The document states that "Westminster's time is coming to an end" and that "momentum is behind our movements", and says the parties believe "the future of our nations belongs in the European Union".

The declaration lands amid conflicting signals over Burnham's own position. He told the House of Commons a fresh Scottish referendum could be held if there was a "clear consensus" north of the border, but Downing Street later wrote to Swinney to say a vote remained "off limits". Mairi McAllan, the Scottish Government's Education Secretary, said in the days before the signing that a referendum was "not off the table". Burnham had already drawn criticism from Sinn Féin, which called his remarks "anti-democratic", after telling broadcasters on 27 August that a vote on Irish unity was "off the table". Downing Street issued a statement the same evening reaffirming the Prime Minister's commitment to "every part" of the Belfast Agreement, "including the principle of consent", and Burnham told the House of Commons on 1 September, in reply to an SNP MP, "I am very aware of every word in the Good Friday agreement, and I will stick to it 100% as Prime Minister."

The pact drew an immediate objection in Northern Ireland. Emma Little-Pengelly, DUP deputy First Minister, said O'Neill "has not sought any agreement or permission from me to travel, attend or sign anything as first minister". O'Neill, for her part, pointed to comments from U.S. President Donald Trump in support of a united Ireland as evidence the debate was "very much alive" and now being had "not just at home, but obviously now internationally as well".

The three leaders' positions differ. Swinney wants a Scottish referendum within five years. Ap Iorwerth has ruled out a referendum during this Senedd term, saying, "I've never been interested in the breakup of the UK." He is pushing instead for the power to call a referendum to be devolved to Wales, and for a standing National Commission to open a public conversation on Wales's constitutional future. He and Swinney separately signed a bilateral cooperation agreement between the Welsh and Scottish governments, the Cytundeb Caerdydd, or Cardiff Agreement, covering seven shared priorities including the cost of living, economic growth, fiscal arrangements and EU relations.

Downing Street's response, hours after the signing, was that the Prime Minister "believes strongly in the Union" and that his focus was on "growth and good jobs" rather than "constitutional debates or further referendums". The rejection came from a Prime Minister who has made devolving power from Westminster one of his stated priorities since taking office on 20 July 2026.

What it means for Cayman

The Cardiff memorandum addresses Scotland, Wales and Northern Ireland, not the Overseas Territories, and nothing in it changes Cayman's own constitutional arrangements. But the principle it asserts, that each nation's people have the right to decide their own constitutional future and that Westminster should not stand in the way, echoes a dispute Cayman has already had with London over Westminster legislating for the territory without its consent.

Under section 51 of the Sanctions and Anti-Money Laundering Act 2018, Westminster required the Secretary of State to prepare, by 31 December 2020, a draft Order in Council "requiring the government of any British Overseas Territory that has not introduced a publicly accessible register of the beneficial ownership of companies within its jurisdiction to do so". Cayman's government at the time objected. Then-Premier Alden McLaughlin called the move "constitutional overreach" and said in May 2018 that the Government was "keeping all options on the table, including a legal challenge". In a July 2022 piece for the UCL Constitution Unit, George Fergusson wrote that the UK's use of such powers over the territories "has some overlap in British politics with the current pressures on the Sewel Convention concerning the application of Westminster legislation on devolved jurisdictions without consent by devolved legislatures".

The same year as the 2018 Act, McLaughlin led a delegation to London for constitutional talks at the Foreign and Commonwealth Office on 7 and 10 December 2018, seeking an assurance that the UK would not legislate for Cayman, directly or indirectly, without at a minimum consulting the Cayman Islands Government, and the removal of the Governor's reserved power to legislate under section 81 of the Constitution. The talks produced the Cayman Islands Constitution (Amendment) Order 2020, made on 11 November 2020. It inserted a new section 126 under which a proposal to apply a UK Act to Cayman, or to extend one by Order in Council, "shall normally be brought by a Secretary of State to the attention of the Premier so that the Cayman Islands Cabinet may signify its view on it", while stating that this "does not affect the power of the Parliament of the United Kingdom to make laws for the Cayman Islands". The same Order removed the UK's power to disallow Cayman laws under section 80, renamed the Legislative Assembly as Parliament and created the office of Parliamentary Secretary. The UK withdrew the proposed removal of section 81 in September 2020 after the Governor had used it to enact the Civil Partnership Law.

Former Premier McKeeva Bush, speaking to The Caymanian Journal (TCJ) on 15 September, put the case for self-determination in plain terms. "Which child in a family growing up and becoming an adult does not want to be independent of his parents," he said.

Asked by e-mail for Premier André Ebanks MP's response to the Cardiff pact, the Office of the Premier said on 16 September that "the Cayman Islands Government generally does not comment on other countries' constitutional discussions". Asked whether the principle argued for in Cardiff had any bearing on the relationship between Cayman and the UK, the office referred TCJ to a response it had given on 11 September to a separate question about the territories' constitutional arrangements. That response said the issue "was a key topic at the Caribbean OT Leaders Caucus" and that "as we continue to develop a more modern constitutional relationship with the UK", the questions raised "will be reported on in due course as matters develop".

The Caucus, which brought together the leaders of Anguilla, Bermuda, the British Virgin Islands, Cayman and Montserrat and the Deputy Premier of the Turks and Caicos Islands in Bermuda from 8 to 10 September, issued an outcome statement affirming "the right of self-determination of the Territories under the Charter of the United Nations", according to a Cayman Islands Government release of 11 September. The 2027 Caucus is to be held in Cayman.

The Office of the Governor was asked for comment by e-mail on 16 September and had not responded by the deadline given. Jane Owen, Governor of the Cayman Islands, had made no public statement on the Cardiff pact at the time of writing.

What happens next

No independence or constitutional referendum has been scheduled anywhere in the UK. Swinney's five-year timeline and ap Iorwerth's call for the power to hold a referendum to be devolved to Wales are requests to Westminster rather than agreed processes, and Downing Street has given no sign that it intends to grant either. Ap Iorwerth's proposed National Commission is a Welsh initiative that needs no Westminster approval. The Good Friday Agreement route to a border poll on Irish unity remains, in law, a decision for the Northern Ireland Secretary, not for O'Neill or Sinn Féin. For Cayman, the notification provision introduced in 2020 remains in place, and so does section 81.