A dramatic change looms in Welsh politics, as internal Labour polling suggests Reform UK could unseat the party in key Senedd seats in 2026, sources have said.
Labour has led every Welsh government since devolution in 1999, but the new proportional election system makes it easier for Reform to gain a bigger number of seats in Wales than it did in Westminster at the general election.
The data circulated within Labour put Reform UK on 25%, with Labour and Plaid Cymru tied on 21%.
The early survey, a year before the Senedd election in May 2026, reflects the growing unease in Labour ranks as the party grapples with declining support in some of its traditional heartlands.
The Labour survey echoes the latest poll from Survation, which showed Reform UK would rise to 24%, scoring even with Plaid Cymru, and Labour securing a narrow win on 27%. The survey showed Labour’s voter retention had weakened, with less than two-thirds of 2024 Labour voters prepared to back the party next year, and Plaid Cymru picking up most of the defectors. Additionally, the pollsters found 67% of those who backed Labour in 2021 would do so next year.
A new Senedd seat projector from a firm called Cavendish Consulting suggests that, on the Survation polling figures, Reform UK is likely to become the official opposition in the Senedd, with Labour winning 28 seats and Reform 27.
While the next election is a while away, there is debate over whether Labour should continue to seek the vote of those who have switched to Reform, or hold on to its progressive voter base in Wales.
A Labour source said the discussions were intensified by criticism from the Welsh first minister, Eluned Morgan, of the UK government’s benefit cut plans. The source said: “We will need to retain a mix of views because we need to secure our loyal Labour base. We may have to give up the fight with Reform in some Welsh areas as it’s just too sticky, but this must only be in Wales and not Westminster.”
Some have pointed to Torfaen in south Wales, which in Westminster is held by the Cabinet Office minister Nick Thomas-Symonds, as one area that will need to keep up the fight with Reform UK.
Government sources have denied its internal polling had predicted an overall Reform UK win but indicated they were braced for a three-way split between Labour, Plaid Cymru and Reform UK, and have accepted that the 2026 Senedd elections would be Welsh Labour’s worst performance in decades.
“Labour in Wales have always been comfortable running against the Conservatives, so this will be a sea change in our politics,” one said.
Internal work has already begun to understand what Welsh voters want, and how Labour should build its core messaging around this.
While the focus will be on whether Labour manages to gain the biggest vote share next year, questions have been raised as to who Reform UK would go into a coalition with if they were to win and what it would mean for the parties’ leaders in Westminster.
A Reform source said the party was “not looking at any coalitions, we are looking to win as many seats as possible in Wales”.
Earlier this year, the Guardian revealed that Labour MPs whose seats are under threat from Reform had set up a pressure group to urge Keir Starmer to take a tougher stance on migration and crime.
In February, the former Labour first minister of Wales Carwyn Jones urged Labour to talk plainly on the doorstep to counter the looming threat of Reform.
Jones said the party should be asking why it was losing “a slice of our vote” to Reform, adding: “One of the things I was always aware of when I was first minister is that you’ve got to sound normal, avoid jargon, talk like somebody who is an ordinary person.”
