The First Ministers of Scotland, Wales and Northern Ireland - John Swinney, Rhun ap Iorwerth and Michelle O’Neill - have signed a memorandum of understanding affirming the regions’ right to leave the United Kingdom. The agreement says: “The political landscape across these islands is changing." During a signing ceremony that took place in the Welsh capital of Cardiff on Monday, the leaders called on the British government to "prepare for, plan and facilitate constitutional change" so that the regions could hold referendums on leaving the UK. "Our insistence is that all parties to the agreement and I'm speaking to the Prime Minister, Andy Burnham in particular, adhere to the spirit and the letter of this, agreement." Mary Lou McDonald, Sinn Féin president, said while addressing a joint press briefing in Cardiff. Discussions about a potential reunification of Ireland intensified amid Sinn Fein’s electoral achievements in Northern Ireland.