Labour has suffered a crushing by-election defeat in one of its safest Welsh seats, as Plaid Cymru captured Caerphilly for the first time in over a century – a result that has sent shockwaves through Welsh Labour as they approach next year’s elections in Wales.
A historic loss for Labour
Plaid’s Lindsay Whittle won with a majority of 3,848 votes, taking 47 per cent of the total and Reform UK in second place with 36 per cent. Labour’s candidate, Richard Tunnicliffe, secured just 11 per cent – a dramatic collapse from 2021’s 13,000-plus votes.
Whittle, a veteran local campaigner who had previously failed 13 times to win the seat, hailed the victory as “a new beginning” for Wales. “The big parties need to sit up and take notice,” he said. “Labour is a dying beast – its century-long grip on Wales is ending.”
Pressure mounts on Starmer
The result marks Labour’s first loss in Caerphilly since the early 1900s and leaves the party without a working majority in the Senedd. Labour now holds 28 of the 60 seats in Cardiff Bay, forcing it to rely on Plaid or independent members to pass key legislation.
Political observers say the defeat exposes the risks of Labour’s shift to the right on issues like immigration and crime, which has alienated parts of its traditional Welsh base. The scandal surrounding former first minister Vaughan Gething’s resignation last year has also damaged the party’s image in Wales.
Reform’s rise and Plaid’s resurgence
The campaign was dominated by fears of a Reform UK upset after polls showed Nigel Farage’s party leading days before the vote. Farage personally visited the constituency three times, but Reform’s candidate Llŷr Powell ultimately fell short.
Despite finishing second, Reform claimed the result was evidence of “a historic realignment” in Welsh politics, while analysts said tactical voting among left-wingers helped Plaid edge the contest.
Rhun ap Iorwerth, Plaid’s leader, said the victory reflected “a hunger for change and a rejection of the status quo.”
Implications for Welsh elections
With Welsh, Scottish and English elections looming in May 2026, the Caerphilly result could signal deeper trouble for Labour. If replicated across Wales, it would threaten Starmer’s authority just two years into his premiership and give fresh momentum to Plaid Cymru’s vision of a more independent, self-governing Wales.
