The Caerphilly by-election will be Keir Starmer’s next big headache
Rhun ap Iorwerth has served as the leader of Plaid Cymru since June 2023 (Alamy)
4 min read
We are about to see a political earthquake in Wales, where people are ready to turn the page on the old order.
A generational shift is happening. This week’s YouGov poll ahead of the May 2026 Senedd election shows Plaid Cymru leading on 30 percent of the vote, ahead of Reform UK on 29 percent and leaving Labour languishing on just 14 percent.
Across Wales, what were once unshakable Labour heartlands are slipping away from them. Losing a Senedd election for the first time ever would surely be the end of Keir Starmer’s leadership. More importantly, it would also mean a fresh start for Wales, under a Plaid Cymru government.
The warning signs couldn’t be starker for Labour as we approach the crucial Caerphilly Senedd by-election on 23 October.
Labour’s grip in Caerphilly has already snapped. Just last week, the Labour council leader resigned from his lifelong party and threw his weight behind Plaid Cymru. Councillor Morgan described his former party as a “busted flush” and that his "moral standing does not allow me to be aligned with the Labour party any longer".
That’s a refrain I hear time and again while campaigning in Caerphilly.
Labour’s repeated misjudgements – from the decision to cut Winter Fuel Payments, to prevaricating as Israel commits genocide in Gaza, to cutting disability support – leads people to conclude they are no different from their disastrous Tory predecessors.
Across Wales and the UK, people are asking whether politics can still make a difference.
People are crying out for new leadership to reverse decline. Caerphilly’s high street tells the story of decades of neglect. Shuttered shops, libraries under threat, public services stretched to breaking point. Parents struggling to make ends meet, young people leaving for opportunities elsewhere, older residents feeling forgotten – these are the lived realities of people here. Out of this hopelessness has grown the fertile ground on which the populist right thrives.
A new paradigm has now emerged in Welsh politics: the two old parties giving way to Plaid Cymru and Reform UK
Labour’s own drift to the right has done nothing to address these problems. By scapegoating refugees, cutting support for the most vulnerable, clamping down on peaceful protest, and promoting hardline figures in its reshuffle, the party has shown it is more interested in playing catch-up with Reform than in setting out a vision of its own.
The recent reshuffle kept in place a Secretary of State for Wales determined to keep our nation silent at the Cabinet table – a move that will further alienate traditional Welsh Labour supporters.
A summer of parodying Nigel Farage on migration revealed a party that has lost touch with its values. We all know the chaos in the asylum system is letting down our communities – it is a problem that must be grappled with – but by accepting Reform’s framing, Labour is only feeding a climate of hatred.
A new paradigm has now emerged in Welsh politics: the two old parties giving way to Plaid Cymru and Reform UK, with starkly different visions for the nation’s future.
Reform is targeting Wales purely to serve its own ambitions for Westminster, backed by enormous resources from Trump-aligned donors with links to fossil fuels and tax havens. Meanwhile, Plaid Cymru has an ambitious programme of government to reinvigorate our public services, revitalise our towns, put the NHS back on track, and give communities a sense of agency once again.
For disillusioned Labour voters who would never support Reform because of its politics of division, staying home is not an option. Only if people come out to vote can we prove that practical, progressive solutions can address real problems instead of stoking fear.
What happens in Caerphilly will echo far beyond its boundaries. Losing a heartland constituency would be disastrous for Keir Starmer. But more importantly, it would prove that Welsh voters are not willing to settle for managed decline.
It will test whether politics can still be a force for hope instead of fear. It will show whether communities are ready to choose fairness, ambition, and Welsh values over division and despair.
We face the very real challenge of the enormous UK resource Reform is throwing at the election. A bottomless pit of money to buy support. Meanwhile, with a much leaner but effective campaign, I am knocking on doors across Caerphilly asking people to put their trust in Plaid Cymru.
This week’s poll is sensational because it proves something powerful. Plaid Cymru is not just challenging the old order – we are ready to replace it. And in Caerphilly, we can show the way.
Rhun ap Iorwerth is the Leader of Plaid Cymru and the Member of the Senedd for Ynys Môn
