Plaid Cymru has hailed its win in the Caerphilly Senedd byelection as a historic moment for Wales, after seizing the seat from Labour and fending off a strong challenge from Reform UK. The result has left the leaders of both Labour and Reform UK wounded, with Plaid's candidate Lindsay Whittle securing 15,961 votes, while Reform UK's Llŷr Powell won 12,113. Labour's vote collapsed in what had been a stronghold, with its candidate Richard Tunnicliffe polling only 3,713 votes.
The Welsh nationalists' triumph was attributed in part to their clear, passionate call for the people of south Wales to reject Reform UK's stance on immigration. Plaid Cymru leader Rhun ap Iorwerth said the people of Caerphilly had chosen 'hope over division and progress over the tired status quo'. He added: 'We are now the real choice for Wales, the only party able to stop billionaire-backed Reform and offer a better future that works for everyone.'
The party stated that the victory marks a seismic political shift in Wales, signalling the collapse of Labour's vote and a new two-horse race between Plaid Cymru and Reform UK ahead of the 2026 Senedd election. Polling expert Sir John Curtice suggested Plaid was well-placed to lead the next Welsh government, but cautioned against assuming Nigel Farage's bubble had burst.
Labour, which has dominated in Wales for a century, now holds just 29 of the 60 Senedd seats, making it more difficult to pass its 2026-27 budget. Welsh first minister Eluned Morgan acknowledged the party had heard frustration on doorsteps and pledged to listen and learn. Deputy first minister Huw Irranca-Davies called on Plaid to discuss the budget, saying: 'It is really incumbent on some of those parties in the Senedd to come and talk to us about how we pass that budget.'
The winning candidate Lindsay Whittle paid tribute to the late Hefin David, whose sudden death prompted the byelection, promising to 'walk the same path that he did'. Reform UK's Powell said the party had learned much about campaigning, which would be put to good use at next year's Senedd elections.
