On Thursday 7 May, Welsh voters will return to the polls. For the first time since its establishment in 1999, Labour is set not only to lose control of the Senedd but also to fail to become the official opposition. Plaid Cymru and Reform UK are anticipated to become the largest two parties, however neither are expected to form a majority. This is due primarily to a change in the electoral system. While the contest between Plaid and Reform is effectively too close to call, tactical voting is likely to give Plaid Cymru the edge and allow Rhun ap lorwerth to become First Minister.
Following the 2024 Senedd Reform Act, elections to the Welsh Senedd now elect 96 members via a closed list proportional system. The country has been divided into 16 multi-member constituencies, with each electing six members to the Senedd. This stands in contrast to the Additional Member System that was used in previous elections which only elected 60 seats. This election also marks the first use of a closed list proportional system in the UK.
Despite the continued rise of Reform across the UK being reflected in Welsh polling, the country's left-wing bloc is much larger than its right. In the 2021 election, the combined vote share of left to centre-left parties was 66pc, with the most recent YouGov poll (27 April to 4 May) putting that number at 59pc. The rise of Reform has also been mirrored by an anti-Reform sentiment, causing a growth trend in Plaid support. This upswell has also been catalysed by a substantial anti-Labour shift, leading to many tactical voters turning to Plaid in an attempt to prevent Reform from becoming the largest party.
As a consequence of the electoral shift to proportional representation and the size of the voting blocs, the likelihood of coalition formation being required is near inevitable. This means that regardless of whether the election is won by Plaid or Reform, it is likely that the new government will be formed and lead by Plaid Cymru. Two caveats which are worth mentioning are the volatility of seat allocation based on small swings under a proportional system, and the lack of polling data in Wales. Since the beginning of the year just 15 polls have been published in Wales, compared to the 98 conducted for the UK as a single entity. Combine this with the volatility of Proportional Representation and we reach a point where forecasting a seat allocation becomes exceptionally difficult. Despite this, key trends can be identified.
The collapse of establishment party support is more pronounced in Wales compared to other areas of the UK. For the first time since its creation, neither the Conservatives nor Labour are expected to become the largest party or form the official opposition. At the 2021 election, the combined regional vote share of the Conservatives and Labour stood at 66pc. The average of the five most recent polls puts their current combined vote share at 25pc (6 April to 4 May). This is an unprecedented shift in Welsh electoral history and points to the birth of a new political age in Wales.
| Party | Predicted Seats | Seat Range |
|---|---|---|
| Plaid Cymru | 35 | 25-42 |
| Reform | 33 | 22-37 |
| Labour | 13 | 4-17 |
| Conservative | 9 | 0-14 |
| Green | 4 | 0-14 |
| Liberal Democrats | 2 | 0-13 |
| Total | 96 |
At the actual election, Plaid Cymru won control of the Welsh Senedd as predicted. The seats won by each party were: Plaid 43 seats, Reform 34, Labour 9, Conservative 7, Green 2, and Lib Dem 1. We predicted a range for Plaid of 25-42 seats, and Plaid outperformed that range by one seat. Every other party's seat total was within our predicted range.
As we predicted, Rhun ap Iorwerth will become the Welsh First Minister, and Reform becomes the opposition.
You can read our original (and time-stamped) prediction Tweet.