Big shock for Labour in Wales as new Westminster poll comes out

Labour would lose the majority of its MPs in Wales at the next election, a new poll has shown. The biggest party would be Plaid Cymru, which currently has just four of the 32 MPs who represent Wales.

The poll by YouGov for ITV Cymru Wales asked people who they would vote for at the next general election - which has to take place before August 2029.

That shows Plaid's support at Westminster has gone up 6% on the last equivalent poll and Reform UK's has dropped by 4%. Labour's support has dropped 5% and leaves them with just 13% of the vote.

The results were:

Plaid Cymru: 29%

Reform UK: 25%

Labour: 13%

Conservatives: 12%

Green Party: 12%

Lib Dem: 6%

Other: 2%

YouGov’s total sample size for the Westminster voting intentions model was 1,205 adults and questions were asked between January 5 and 12, 2026.

This result came as another poll looked at the Senedd voting intention.

That poll showed Labour is projected to fall to a catastrophic defeat in May's Senedd election while Plaid Cymru becomes overwhelmingly the largest party. 

It showed a Plaid surge to go further ahead of Reform in the run up to the vote in May. Analysis of the poll suggests Labour has less support than the Green Party and may have as few as eight out of the 96 seats in the Senedd after May.

People were asked who they plan to vote for in the Senedd election in May, and the results echo what we have seen before - that Labour is in serious trouble in Wales, and Plaid Cymru and Reform UK will be the two largest parties.

Plaid Cymru's projected vote share has increased from 30% in the last equivalent poll in September, to 37%. Reform's support has dropped in this poll from 29% in September to 23% now.