For more than a century, Labour has been the dominant force in Caerphilly, a Welsh constituency that has never voted for another party in either Westminster or Senedd elections. Yet, with just days to go before the by-election scheduled for October 23, 2025, a new poll has sent shockwaves through the political landscape, suggesting that Labour’s unbroken run is on the verge of a dramatic end.
According to a Survation poll conducted for Camlas and published on October 16, 2025, Labour is languishing in a distant third place with just 12% of the vote. Reform UK leads the field with 42%, while Plaid Cymru is close behind at 38%. The poll, which surveyed 501 people in Caerphilly, marks the first time the party has faced such a dire prediction in its traditional heartland. The late Hefin David, Labour’s previous Senedd member, won the seat in 2021 with a commanding 46% of the vote, underscoring the scale of the party’s collapse in just four years.
“Welsh politics is on the cusp of an unprecedented transformation,” Damian Lyons Lowe, Chief Executive of Survation, told LabourList. “The Labour and Conservative parties previously took a combined 63% of Caerphilly’s Senedd vote in 2021 – our polling indicates this may have plummeted to just 16% as both have seen an extreme fragmentation of their vote to both Reform and Plaid.”
The numbers are, indeed, jaw-dropping. Labour’s share of the vote has dropped by more than 30 points since the 2021 Senedd election. National polling reflects a similar trend, with Labour’s support in Wales falling to just 14%, down from 40% in 2021, according to WalesOnline. The poll’s findings suggest not only a local crisis for Labour but also hint at a broader realignment in Welsh politics ahead of the 2026 Senedd elections.
What’s driving this seismic shift? The data points to a dramatic generational and ideological realignment. Reform UK is drawing strong support from older voters—49% of those aged 55 and above back the party, and it has managed to attract a massive 70% of Conservative voters from the 2021 Senedd election. Plaid Cymru, meanwhile, is dominating among younger voters, with 50% support among those aged 18 to 34. Plaid is also pulling in 31% of 2021 Labour voters and 19% of 2021 Conservative voters who are not enthused by the prospect of Reform’s rise.
Labour’s traditional base in Caerphilly has fragmented dramatically. Only one in three (33%) of its 2021 voters remain loyal. The rest have split—31% now support Plaid Cymru, and 26% have shifted to Reform. Labour’s remaining vote is increasingly concentrated among its older core supporters, with just 15% of voters aged 55 and over still backing the party. Meanwhile, Conservative support in the constituency has all but evaporated, with around 70% of 2021 Conservative voters now backing Reform.
Rhodri ab Owen, managing director of Camlas Public Affairs, told WalesOnline, “All eyes have been on Caerphilly, as the by-election campaign is seen as a reflection of what is to come when Welsh voters head to the polls in 2026. The battle lines of Welsh politics have been redrawn. A dramatic generational shift is exhibited to be driving the future of Welsh politics as Reform and Plaid’s bases are concentrated in older and younger voter clusters respectively. Welsh Labour’s electoral dominance is potentially coming to an end with their dramatic 34 point drop in the polls and their support divided between Reform and Plaid Cymru.”
For Labour, the poll is a sobering wake-up call. A Welsh Labour source, quoted by LabourList, acknowledged the difficulties: “We’re not shying away from the fact this has been a difficult campaign at a difficult time for governments both here and in London. We’ve spoken to tens of thousands of voters since the start of this by-election and we’re hearing those frustrations on the doorsteps. But there’s also real concern about letting Reform in. The party’s campaign’s been focused on the people who live here and what we can deliver by May. The sample size of the latest poll is smaller than the number of people we talk to in a day. There’s a reason why constituency level polling isn’t widely done. It’s unreliable.”
Yet, despite Labour’s attempt to cast doubt on the poll’s predictive power, the sheer scale of the projected shift is difficult to ignore. The poll’s 501-strong sample may be modest, but it is the first to specifically gauge the mood in Caerphilly just days before the by-election. Its findings are echoed by national trends and underline a broader malaise afflicting Labour in Wales.
The implications reach far beyond a single seat. Should Labour lose Caerphilly, the party would face a significant hurdle in passing a Budget next year. More broadly, as Damian Lyons Lowe noted, “While Labour’s one hundred year long unbeaten record in Caerphilly’s Senedd and Westminster elections is highly likely to be coming to an end, this type of result being replicated nationally will also see the end of over twenty years of Labour Welsh Government dominance, with Reform or Plaid the likely party of power in 2026.”
Plaid Cymru, sensing an opportunity, has made a direct appeal to voters. A party spokesperson said, “This poll confirms that the by-election is a two-horse race between Reform and Plaid Cymru. There is only one choice for those who want to defeat the ex-Tories and their politics of division – that choice is a vote for Plaid Cymru’s excellent candidate Lindsay Whittle. Lindsay has dedicated his whole life to serving the communities of Caerphilly. He is the only credible option for voters who want a principled, passionate and hard-working Senedd member and we urge everyone who wants to beat Reform to back him next Thursday.”
As the campaign enters its final days, both Reform and Plaid are vying for the top spot, with Labour fighting to avoid a historic defeat. The by-election has become a microcosm of wider shifts in Welsh politics, with generational divides, shifting loyalties, and the collapse of old certainties all playing out in real time.
With the by-election set for October 23, all eyes are on Caerphilly. The outcome may well set the stage for the next chapter in Wales’s political story—one in which Labour’s dominance is no longer assured, and new forces are stepping into the breach.
