A new MRP forecast by research group More in Common suggests Reform UK is now the dominant political force across South West Wales, overtaking Labour in multiple constituencies and setting the stage for a dramatic shift in both Westminster and Senedd representation.
The July 2025 model, based on polling of over 10,000 UK adults, projects Reform UK to win 290 seats nationally, with Labour trailing on 126 and the Conservatives collapsing to 81. But the most striking changes are happening closer to home—particularly in Llanelli, where a once-safe Labour seat is now projected to fall decisively to Reform.
Westminster Projections: Reform Gains Across the Region
| Constituency | Projected Winner | Reform UK | Labour | Plaid Cymru | Conservative | Lib Dem | Green | Others | Outcome |
|---|---|---|---|---|---|---|---|---|---|
| Llanelli | Reform UK | 44% | 15% | 27% | 6% | 3% | 1% | 5% | Reform Gain from Labour |
| Swansea West | Reform UK | 29% | 20% | 21% | 10% | 12% | 4% | 4% | Reform Gain from Labour |
| Neath & Swansea East | Reform UK | 26% | 23% | 22% | 8% | 8% | 3% | 11% | Reform Gain from Labour |
| Gower | Reform UK | 32% | 30% | 2% | 17% | 2% | 4% | 15% | Reform Gain from Labour |
| Bridgend | Reform UK | 44% | 22% | 13% | 6% | 8% | 4% | 4% | Reform Gain from Labour |
| Aberafan Maesteg | Reform UK | 39% | 21% | 13% | 7% | 14% | 2% | 5% | Reform Gain from Labour |
| Caerfyrddin | Plaid Cymru | 39% | 12% | 39% | 9% | 1% | 6% | 4% | Plaid Hold |
| Ceredigion Preseli | Plaid Cymru | 52% | 8% | 52% | 9% | 4% | 6% | 2% | Plaid Hold |
| Mid & South Pembs | Reform UK | 34% | 19% | 5% | 26% | 5% | 4% | 7% | Reform Gain from Conservative |
| Brecon, Radnor & Cwm Tawe | Reform UK | 34% | 16% | 16% | 8% | 19% | 6% | 1% | Reform Gain from Liberal Democrat |
Llanelli: A Case Study in Reform’s Rise
The most symbolic shift is in Llanelli, where Labour veteran Dame Nia Griffith is now projected to lose her seat to Reform UK by a 29-point margin. This follows a series of local breakthroughs:
- In 2024, Gareth Beer of Reform UK came within a few hundred votes of unseating Griffith.
- In May 2025, Michelle Beer, Gareth’s wife, won a landslide victory in the Lliedi ward of Carmarthenshire County Council, defeating Labour by over 250 votes (full story).
- The Beers’ growing local profile has made Llanelli a bellwether for Reform’s national momentum.
Reform’s Local Ground Game: Beyond Llanelli
Reform’s rise isn’t limited to Llanelli. In Bridgend, the party recently won a council by-election in Pyle, Kenfig Hill and Cefn Cribwr, beating Labour by just 30 votes (coverage). That victory, combined with the MRP projection of a 22-point lead in the parliamentary seat, suggests a deep shift in voter sentiment.
What This Means for the 2026 Senedd Election
The next Senedd election will be the first under a new proportional voting system, with 96 MSs elected from 16 six-member constituencies. Based on current polling, Reform UK is projected to win the most seats in the Senedd—but not a majority.
According to Swansea Bay News’s earlier analysis (read more), the most likely outcome remains a Plaid–Labour coalition, despite Reform’s lead in vote share. This is due to the proportional system rewarding broad but balanced support across constituencies.
Updated Senedd Projections for Swansea Bay Region
| Senedd Constituency | Composed of Parliamentary Seats | Projected MSs (by party) |
|---|---|---|
| Gŵyr Abertawe | Swansea West + Gower | 2 Reform, 2 Labour, 1 Plaid, 1 Lib Dem |
| Brycheiniog Tawe Nedd | Brecon, Radnor and Cwm Tawe + Neath and Swansea East | 2 Reform, 2 Labour, 1 Plaid, 1 Other |
| Afan Ogwr Rhondda | Aberafan Maesteg + Rhondda and Ogmore | 3 Reform, 2 Labour, 1 Lib Dem |
| Sir Gaerfyrddin | Llanelli + Caerfyrddin | 3 Plaid, 2 Reform, 1 Labour |
| Ceredigion Penfro | Ceredigion Preseli + Mid and South Pembrokeshire | 3 Reform, 2 Conservative, 1 Labour |
| Pen-y-bont Bro Morgannwg | Bridgend + Vale of Glamorgan | 2 Labour, 2 Reform, 1 Conservative, 1 Plaid |
These estimates reflect the July 2025 MRP vote shares applied to the D’Hondt method. Final outcomes will depend on turnout, candidate lists, and campaign dynamics.
A Region in Political Flux
The combined effect of Westminster polling, local by-election results, and Senedd projections suggests South West Wales is undergoing a historic political realignment:
- Reform UK is now the leading party in most local constituencies
- Labour’s dominance is eroding, especially in working-class and post-industrial areas
- Plaid Cymru remains strong in rural constituencies but is not expanding beyond its base
- The Conservatives risk being wiped out in several seats unless they reverse their polling decline
For more on how these changes could affect your community, follow the Politics section of Swansea Bay News.
