Plaid Win, Reform UK Surge, Labour Humiliation: Caerphilly By-Election
The Caerphilly by-election has shaken Welsh politics to its core. In this Senedd Sources flash reaction episode, Calum Macdonald, Jo Kiernan and Craig Lawton unpack a dramatic night for Welsh democracy.
👉 Plaid Cymru has claimed victory with 47% of the vote — the party’s first win in Caerphilly for 100 years — while Labour crashed to third, and Reform UK surged into second with 36%. What does this mean for Keir Starmer’s Labour, for Nigel Farage’s Reform movement, and for Welsh politics ahead of the 2026 Senedd election?
In this episode:
Why turnout hit a record 50% — and what it tells us…
The skinny
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