Plaid Wins Caerphilly; Labour Falls to Third

Plaid Cymru won the Caerphilly Senedd by-election with about 47% of the vote, Reform UK surged into second with roughly 36%, and Welsh Labour collapsed to around 11%, finishing third. The contest, triggered by the sudden death of Labour MS Hefin David, produced a swing of nearly 27% from Labour in a high-turnout contest. Commentators and pollsters warned the outcome is a historic defeat for a former Labour stronghold and could undermine Labour’s prospects ahead of next May’s Senedd election and complicate Welsh government business. Analysts said the result exposed tactical voting and a fragmented Welsh political landscape, with Plaid framing the vote as blocking Reform and offering an alternative. Separately, three Glasgow councillors defected from the Scottish Greens to join Your Party, giving that movement its first elected representatives in Scotland and highlighting wider volatility in UK politics.