Plaid Cymru has won the Caerphilly Senedd by-election in a dramatic result that ended thirty years of Labour dominance in the south Wales seat [The Senedd is the devolved Welsh assembly]. Veteran councillor Lindsay Whittle secured victory with a commanding lead over Reform UK, while Labour slumped to just 11% of the vote and the Conservatives collapsed to 2%.

The two Westminster heavyweights together attracted only 13% support, marking one of the weakest showings for both parties in modern Welsh political history. Reform UK placed second on 36%, but Plaid’s decisive win underscored its growing strength ahead of next year’s Welsh elections.

Whittle, 70, celebrated his first electoral triumph after nearly five decades of campaigning. “I’ve been standing since I was a teenager, and finally, the people of Caerphilly have put their trust in Plaid Cymru,” he said after the result was declared at Caerphilly Leisure Centre.

Plaid leaders said the vote signalled a turning point in Welsh politics and evidence that Labour’s long grip on power is slipping. The party now hopes to build on its momentum to challenge Labour’s 27-year rule in the Senedd when Wales votes again next May.

For Labour, the defeat in a constituency linked to figures like Nye Bevan and Neil Kinnock raises stark questions about its hold over its traditional heartlands.