Reform UK pulls ahead as Plaid slips and Labour edges back in new Senedd poll

From three‑way squeeze to Reform lead

Just a month ago, Swansea Bay News reported on a YouGov survey that suggested a three‑way squeeze at the top of Welsh politics, with Plaid Cymru and Reform UK neck‑and‑neck and Labour slumping to a historic low. The latest Barn Cymru/Beaufort Research poll, however, points to a decisive shift.

Reform UK has surged to 30% of the vote, pulling clear of its rivals and establishing itself as the largest party in Wales. Labour has edged back to 23%, recovering some ground but still far from its traditional dominance, while Plaid Cymru has slipped into third place on 22%. The Conservatives continue their downward slide, now on just 11%, while the Greens have quietly climbed to 9% — enough for a projected foothold in the Senedd under the new system.

When translated into seats under the new 96‑member system, the numbers would give Reform 37, Plaid 25, Labour 24, the Conservatives 7, the Greens 2 and the Liberal Democrats 1. That leaves no party close to the 49 seats needed for a majority.

Coalition arithmetic

The most likely outcome on these figures would be a Plaid‑led coalition with Labour, which together would command 49 seats — just enough for a working majority. By contrast, a Reform‑Conservative bloc would fall short, with only 44 seats between them, leaving Reform as the largest party but unable to govern without further partners.

A Plaid‑Labour‑Green arrangement would be more comfortable at 51 seats, but it’s worth stressing that the Greens currently hold no seats in the Senedd — so any such deal would only be possible if they do indeed win representation next May.

Updated Senedd projections for South West Wales

Compared with our September projections, Reform strengthens in Swansea‑based constituencies, gaining an extra seat in both Gŵyr Abertawe and Brycheiniog Tawe Nedd. Labour weakens in Brycheiniog Tawe Nedd, dropping from two seats to one, while Plaid picks up in Afan Ogwr Rhondda. The most dramatic change is in Ceredigion Penfro, where Plaid is now projected to take three seats, wiping out the Conservatives’ Pembrokeshire foothold.

Regional and demographic divides

The Beaufort poll also highlights sharp contrasts beneath the headline numbers. Reform’s surge is concentrated in Cardiff and South East Wales, where it polls 37%, while Plaid remains competitive in North and Mid Wales. In the South West and Valleys, the three main parties are tightly bunched, with Reform on 28%, Labour 26% and Plaid 25%.

Demographically, Reform’s support skews older and working‑class: it leads by a wide margin among voters aged 55+ and among those in the C2DE social grades. Labour and Plaid perform better among younger and professional voters, while the Greens’ rise is driven in part by stronger support among women.

Language also plays a role. Welsh speakers overwhelmingly back Plaid Cymru (45%), while non‑speakers tilt towards Reform (33%). This cultural divide underlines the different electoral coalitions each party is trying to build.

Caerphilly by‑election

The timing of the poll is significant. On Thursday, voters in Caerphilly will choose a new MS following the death of Labour’s Hefin David. Labour currently holds 30 of the 60 Senedd seats, relying on support from other parties — particularly the sole Liberal Democrat, Jane Dodds — to pass legislation and the annual budget.

If Labour were to lose Caerphilly, its total would fall to 29 seats, making it much harder to govern. Even with Lib Dem support, the party would fall short of a working majority, forcing it to seek wider co‑operation with Plaid Cymru or others to get bills through. Local polling suggests the contest is shaping up as a two‑horse race between Reform and Plaid, underlining the scale of the threat to Labour’s hold on the seat.

Polling caveats

As with all opinion polls, these figures come with a margin of error — typically around three percentage points either way. Different polling companies also use different methods of weighting and sampling, which can produce variations in headline numbers. The contrast between September’s YouGov poll (which had Plaid narrowly ahead) and October’s Beaufort poll (which puts Reform clearly in front) is a reminder of that.

And, crucially, the next Senedd election is not until May 2026. With more than six months to go, voter sentiment can and will shift. These polls are a snapshot of opinion today, not a prediction of the final result.

Outlook: a fragmented Senedd ahead

Taken together, the September YouGov poll and the October Beaufort figures chart a rapid evolution in Welsh politics: from a three‑way squeeze to a Reform‑led race, with Plaid and Labour battling for second place and the Conservatives reduced to the margins. With no party projected to govern alone, the next Senedd looks set to be defined by coalition deals — and by whether Labour can steady its position in the months ahead.