October’s by-election, set at the southern end of the Rhymney Valley, defied expectations and polling that predicted a Reform UK win after  a close race with Plaid Cymru. Instead, Plaid’s candidate Lindsay Whittle came out on top by a considerable margin, garnering 47.4% of the vote, leaving Reform UK’s Llŷr Powell trailing behind at 36% of the vote.

Voters came out in their droves for this by-election. At 50.43%, it broke a record as the highest turnout ever for a devolved by-election in Wales. Previously, the highest turnout in a Senedd by-election didn’t even break 50%, totalling 45.2% in Blaenau Gwent nineteen years ago.

For Lindsay Whittle, the win was particularly euphoric. After standing thirteen other times in Caerphilly elections, it was fourteenth time lucky. In his victory speech, he made light of the situation: “Ladies and gentlemen, you will for give me, I’m not used to speaking first in these election counts.” 

However, he balanced his elation with a poignant tribute to the tragic circumstances  which triggered this by-election: the sudden death of the previous MS, Hefin David. He continued: “[Hefin] will be a hard act to follow. I will never fill his shoes. But I promise you, I will  walk the same path that he did. And I can pay no finer tribute to an excellent man.”

Success for the Welsh nationalist party demonstrates a progressive bloc of voters forming to keep Reform out, partly resulting from tactical voting. The incentive to tactically vote will reduce under the new proportional voting system in next year’s Senedd election, but the result still positions Plaid as the leading force for left-leaning voters to unite behind in 2026.

Meanwhile, a ruinous night unfolded for Reform. Despite confident beginnings with senior figures like Nigel Farage and Zia Yusuf  visiting on polling day, this began to dwindle as time drew closer to the result. By the time of the declaration, Reform supporters had largely left the count, and their candidate Llŷr Powell refused to give a speech.

Clearly, Reform was disappointed. After all, substantial resources went into this by-election, from visits by senior MPs, to their own Caerphilly headquarters set up on the town’s high street.

However, there is a silver lining for the party. 36% of the vote is not insignificant, and similar numbers in the Senedd election will see them  win seats. Just like how Plaid has been positioned as a leading force, Reform have proved themselves as the right-wing alternative. Their real challenge will be combatting the progressive voting bloc, and finding parties open to a coalition if they were to form a government next  May.

For the traditional stalwarts of UK politics, the result was more predictable – and it was as damning as expected. Labour’s more than century-long dominance in Caerphilly came to a crashing halt, attracting just 11% of voters, while the Conservatives didn’t even break double digits, only managing 2%.

These catastrophic results only reiterate the electoral oblivion which awaits these parties in future elections. Welsh Labour’s heartlands are  no longer dependable – they’ve become disillusioned with the party, as proven by approval ratings which suggest that over half of Welsh adults disapprove of their government.

As work gets underway for Lindsay Whittle as the newly sworn-in Member of the Senedd for Caerphilly, so too does the work towards the wider contest for the whole of Wales.