Full Breakdown
Plaid Cymru Leads Final YouGov Poll Ahead of 2026 Senedd Election
5/6/2026, 2:41:33 AM
Final YouGov MRP Poll Predicts Plaid Cymru Lead
A YouGov multi-level regression and post-stratification (MRP) model commissioned by ITV Cymru Wales released figures on 4 May 2026. From 2,391 Welsh adults (aged 16+), it projects Plaid Cymru 33 % of the Senedd vote, Reform UK 29 %, Labour 12 %, Conservatives 9 %, Greens 8 % and Liberal Democrats 6 %.
New Constituencies and Proportional Representation
The election uses sixteen drawn constituencies, each electing six members via the d’Hondt formula. Voters mark a single cross for a party.
Vote Shares, Seat Projections and Voter Priorities
The model projects a 96-seat Senedd: Plaid Cymru 43, Reform UK 34, Labour 12, Conservatives 4, Greens 2, Liberal Democrats 1. 43 % expect Plaid Cymru to lead the government, 15 % Reform UK. Government type is 44 % single-party, 32 % coalition. Issues: “Stopping Reform” and “Immigration”.
Official Statements & Responses
Analysts at Cardiff University’s Welsh Governance Centre said the poll clarifies the contest’s shape but precise seat totals remain uncertain, noting Plaid Cymru’s modest lead and chance of a progressive majority. The political editor warned that tiny, undetectable voter shifts could alter the outcome.
Criticism & Opposition
Analysts warned that tiny, undetectable shifts in voter behaviour could change the result, emphasizing that it remains unclear which party would emerge as the largest or be able to form a government.
Conflicting Reports & Gaps
A Westminster-focused YouGov poll of 1,125 adults (aged 18+) gave Plaid Cymru 30 % and Reform UK 26 %, with Greens 13 % and Conservatives 12 %, lower than Senedd poll shares. The difference reflects sample size and possibly divergent attitudes toward devolved versus UK-wide elections. The poll does not cover post-election coalition talks or new system’s impact on smaller parties.
Verbatim Quotes
- “What this final poll tells us is that the broad shape of Thursday’s result is now fairly clear, even if precise seat totals remain uncertain.” — Dr Jac Larner, Welsh Governance Centre, Cardiff University
- “even tiny changes that are too small for polls to detect could mean the eventual result is very different” — Dr Jac Larner
- “This latest poll reinforces the message from a year of polls: this week’s vote will be historic and seems all but certain to lead to a change in who leads the Welsh Government.” — Adrian Masters, ITV Cymru Wales Political Editor
- “still impossible to say if Plaid Cymru or Reform UK will be the largest party and who, if anyone, can form a government” — Adrian Masters
What’s Next
Polling stations open on Thursday, 7 May 2026. Voters receive party-list ballots for their six-member constituency; seats are allocated with the d’Hondt formula. Outcome will decide if Wales is governed by a single-party administration, a coalition or a minority government, and if Plaid Cymru can secure a progressive majority.
