Plaid Cymru Key Battleground Seats

These are Plaid Cymru's most marginal seats, based on the lowest percentage swing required for the result to differ from VoteClimate's Forecast For The Next General Election.

First we list the seats where, based on current opinion polls, Plaid Cymru should expect to win by up to 10%. Then we list the seats where Plaid Cymru are predicted to be within 10% of winning the seat.

These are seats where Registering with VoteClimate will have the maximum influence on party policies. So if you have climate-concerned friends and family in these areas, please invite them to join us!

Forecast vote shares (GB): Reform: 27% | Labour: 18.8% | Conservative: 18.3% | Green: 14.5% | Liberal Democrat: 12.2%

[Last updated: June 2026]

Constituency Plaid Cymru Forecast Expected Competitor Predicted Majority
/ Votes Required
Blaenau Gwent and Rhymney 1st 13,175 Labour 6,330 6,845 9.8%
Cardiff West 1st 18,327 Reform 10,987 7,340 9.7%
Bangor Aberconwy 1st 17,447 Reform 11,100 6,347 9.0%
Caerphilly 1st 15,648 Reform 12,224 3,424 4.7%
Cardiff North 1st 15,397 Reform 12,652 2,745 3.8%
Cardiff South and Penarth 1st 11,788 Reform 9,758 2,030 2.8%
Cardiff East 1st 11,939 Reform 10,110 1,829 2.5%
Llanelli 1st 16,588 Reform 15,101 1,487 2.1%
Swansea West 1st 11,666 Reform 10,869 797 1.1%
Pontypridd 1st 13,251 Reform 12,577 674 0.9%
Wrexham 1st 12,968 Reform 12,412 556 0.8%
Montgomeryshire and Glyndwr 1st 14,233 Reform 13,920 313 0.4%
Aberafan Maesteg 1st 12,608 Reform 12,434 174 0.2%
Vale of Glamorgan 1st 13,415 Reform 13,383 32 0.0%
Clwyd East 1st 14,339 Reform 14,309 30 0.0%
Monmouthshire 1st 13,021 Reform 13,016 5 0.0%
Clwyd North 2nd 12,298 Reform 12,746 448 0.6%
Brecon, Radnor and Cwm Tawe 2nd 11,849 Reform 12,318 469 0.6%
Merthyr Tydfil and Aberdare 2nd 12,103 Reform 12,797 694 0.9%
Gower 2nd 14,368 Reform 15,119 751 1.0%
Bridgend 2nd 12,253 Reform 13,159 906 1.2%
Mid and South Pembrokeshire 2nd 13,137 Reform 14,226 1,089 1.4%
Rhondda and Ogmore 2nd 12,782 Reform 13,996 1,214 1.6%
Neath and Swansea East 2nd 13,612 Reform 15,141 1,529 2.0%
Newport West and Islwyn 2nd 12,452 Reform 14,060 1,608 2.1%
Newport East 2nd 10,543 Reform 12,577 2,034 2.7%
Torfaen 2nd 10,220 Reform 12,644 2,424 3.4%
Alyn and Deeside 2nd 11,303 Reform 15,568 4,265 5.6%

See also: Electoral Analysis