Overview

• A YouGov poll for ITV Cymru Wales/Barn Cymru, conducted September 4–10 with 1,232 respondents, puts Plaid Cymru on 30%, Reform UK on 29% and Labour on 14%.
• Dr Jac Larner’s projection for the expanded 96-seat Senedd translates the poll into Plaid 38 seats, Reform 37, Labour 11, Conservatives 6, Liberal Democrats 3 and Greens 1.
• Larner reports Plaid’s support holding steady, Reform’s surge drawing mainly from former Conservative voters and Labour losing voters to Plaid, the Greens and to a lesser extent Reform.
• Next May’s election will use new boundaries and a single-vote system for 96 members, increasing seat volatility and making post-election coalition building likely.
• The Caerphilly by-election on October 23, called after Hefin David’s death, is viewed as an early test of the shifting political landscape.