Rhun ap Iorwerth (L) of Plaid Cymru in Wales, Scottish Nationalist Party (SNP) leader John Swinney (2nd L) and Mary Lou McDonald (2nd R), president of Irish Republicans Sinn Fein look on as Michelle O'Neill (R), vice president of Irish Republicans Sinn Fein signs a memorandum of understanding as they attend a meeting in Cardiff, Wales on September 14, 2026, to press for self-determination votes in their territories. The leaders of the main Scottish, Northern Irish and Welsh parties on September 14 declared their right to "self determination" in a joint agreement signed at a rare meeting in the Welsh capital Cardiff. (Photo by Adrian DENNIS / AFP via Getty Images)