Below are lists of Conservative marginal seats showing which constituencies won in the latest elections can be most easily lost.
Historical
Below is the Conservative defence list consisting of Conservative held marginal seats for the 2029 general election based on the 2024 boundaries. These marginal constituencies are ordered from the most vulnerable seats to the safest.
| Rank | Constituency | Region | Majority | Swing to Defeat | |
|---|---|---|---|---|---|
| 1. | Basildon and Billericay | East of England | 20 | 0.02% | |
| 2. | Devon Central | South West | 61 | 0.06% | |
| 3. | Havant | South East | 92 | 0.11% | |
| 4. | Exmouth and Exeter East | South West | 121 | 0.12% | |
| 5. | Beverley and Holderness | Yorkshire and the Humber | 124 | 0.14% | |
| 6. | Bromley and Biggin Hill | London | 302 | 0.32% | |
| 7. | Fylde | North West | 561 | 0.58% | |
| 8. | Broadland and Fakenham | East of England | 719 | 0.73% | |
| 9. | Godalming and Ash | South East | 891 | 0.81% | |
| 10. | Wrekin, The | West Midlands | 883 | 0.88% | |
| 11. | Wyre Forest | West Midlands | 812 | 0.90% | |
| 12. | Gordon and Buchan | Scotland | 878 | 1.00% | |
| 13. | Dumfries and Galloway | Scotland | 930 | 1.02% | |
| 14. | Tatton | North West | 1,136 | 1.09% | |
| 15. | Harwich and Essex North | East of England | 1,162 | 1.21% | |
| 16. | Farnham and Bordon | South East | 1,349 | 1.27% | |
| 17. | Hampshire East | South East | 1,275 | 1.27% | |
| 18. | Bedfordshire Mid | East of England | 1,321 | 1.33% | |
| 19. | Staffordshire Moorlands | West Midlands | 1,175 | 1.36% | |
| 20. | Hereford and Herefordshire South | West Midlands | 1,279 | 1.40% | |
| 21. | Huntingdon | East of England | 1,499 | 1.44% | |
| 22. | Skipton and Ripon | Yorkshire and the Humber | 1,650 | 1.54% | |
| 23. | Shropshire South | West Midlands | 1,624 | 1.57% | |
| 24. | Faversham and Mid Kent | South East | 1,469 | 1.58% | |
| 25. | Dorset North | South West | 1,589 | 1.60% | |
| 26. | Romford | London | 1,463 | 1.66% | |
| 27. | Bridgwater | South West | 1,349 | 1.68% | |
| 28. | Spelthorne | South East | 1,590 | 1.72% | |
| 29. | Keighley and Ilkley | Yorkshire and the Humber | 1,625 | 1.76% | |
| 30. | Maidstone and Malling | South East | 1,674 | 1.80% | |
| 31. | Bognor Regis and Littlehampton | South East | 1,765 | 1.85% | |
| 32. | Devon South West | South West | 2,112 | 2.02% | |
| 33. | Hornchurch and Upminster | London | 1,943 | 2.07% | |
| 34. | Romsey and Southampton North | South East | 2,191 | 2.19% | |
| 35. | Stockton West | North East | 2,139 | 2.20% | |
| 36. | Leicestershire Mid | East Midlands | 2,201 | 2.29% | |
| 37. | Croydon South | London | 2,313 | 2.34% | |
| 38. | Harborough, Oadby and Wigston | East Midlands | 2,378 | 2.36% | |
| 39. | Essex North West | East of England | 2,610 | 2.40% | |
| 40. | Herne Bay and Sandwich | South East | 2,499 | 2.56% | |
| 41. | Sutton Coldfield | West Midlands | 2,543 | 2.63% | |
| 42. | Bexhill and Battle | South East | 2,657 | 2.78% | |
| 43. | Daventry | East Midlands | 3,012 | 2.84% | |
| 44. | Chester South and Eddisbury | North West | 3,057 | 2.91% | |
| 45. | Bromsgrove | West Midlands | 3,016 | 2.99% | |
| 46. | Reigate | South East | 3,187 | 3.00% | |
| 47. | Suffolk South | East of England | 3,047 | 3.12% | |
| 48. | Hampshire North West | South East | 3,288 | 3.23% | |
| 49. | Broxbourne | East of England | 2,858 | 3.33% | |
| 50. | Norfolk Mid | East of England | 3,054 | 3.33% | |
| 51. | Newark | East Midlands | 3,572 | 3.34% | |
| 52. | Cotswolds North | South West | 3,357 | 3.34% | |
| 53. | Northamptonshire South | East Midlands | 3,687 | 3.43% | |
| 54. | Wiltshire South West | South West | 3,243 | 3.51% | |
| 55. | Aberdeenshire West and Kincardine | Scotland | 3,441 | 3.51% | |
| 56. | Suffolk West | East of England | 3,247 | 3.52% | |
| 57. | Goole and Pocklington | Yorkshire and the Humber | 3,572 | 3.59% | |
| 58. | Bridlington and the Wolds | Yorkshire and the Humber | 3,125 | 3.64% | |
| 59. | Old Bexley and Sidcup | London | 3,548 | 3.72% | |
| 60. | Braintree | East of England | 3,670 | 3.74% | |
| 61. | Gainsborough | East Midlands | 3,532 | 3.78% | |
| 62. | Salisbury | South West | 3,807 | 3.79% | |
| 63. | Brigg and Immingham | Yorkshire and the Humber | 3,243 | 3.81% | |
| 64. | Torridge and Tavistock | South West | 3,950 | 3.89% | |
| 65. | Castle Point | East of England | 3,251 | 4.00% | |
| 66. | Hamble Valley | South East | 4,802 | 4.45% | |
| 67. | Sleaford and North Hykeham | East Midlands | 4,346 | 4.47% | |
| 68. | Hertfordshire South West | East of England | 4,456 | 4.62% | |
| 69. | Suffolk Central and Ipswich North | East of England | 4,290 | 4.62% | |
| 70. | Wetherby and Easingwold | Yorkshire and the Humber | 4,846 | 4.64% | |
| 71. | Leicester East | East Midlands | 4,426 | 4.74% | |
| 72. | Dumfriesshire, Clydesdale and Tweeddale | Scotland | 4,242 | 4.80% | |
| 73. | Grantham and Bourne | East Midlands | 4,496 | 4.87% | |
| 74. | Isle of Wight East | South East | 3,323 | 4.88% | |
| 75. | Chingford and Woodford Green | London | 4,757 | 4.90% | |
| 76. | Solihull West and Shirley | West Midlands | 4,620 | 4.93% | |
| 77. | Wiltshire East | South West | 4,716 | 5.00% | |
| 78. | Witham | East of England | 5,145 | 5.08% | |
| 79. | Meriden and Solihull East | West Midlands | 4,584 | 5.20% | |
| 80. | Aldridge-Brownhills | West Midlands | 4,294 | 5.25% | |
| 81. | Bedfordshire North | East of England | 5,414 | 5.25% | |
| 82. | Leicestershire South | East Midlands | 5,506 | 5.36% | |
| 83. | Buckinghamshire Mid | South East | 5,872 | 5.44% | |
| 84. | Sevenoaks | South East | 5,440 | 5.45% | |
| 85. | Orpington | London | 5,118 | 5.55% | |
| 86. | Norfolk North West | East of England | 4,954 | 5.56% | |
| 87. | Hinckley and Bosworth | East Midlands | 5,408 | 5.66% | |
| 88. | Beaconsfield | South East | 5,455 | 5.71% | |
| 89. | Rayleigh and Wickford | East of England | 5,621 | 5.86% | |
| 90. | Melton and Syston | East Midlands | 5,396 | 5.87% | |
| 91. | Louth and Horncastle | East Midlands | 5,506 | 5.92% | |
| 92. | Worcestershire West | West Midlands | 6,547 | 5.99% | |
| 93. | New Forest West | South East | 5,600 | 6.04% | |
| 94. | Fareham and Waterlooville | South East | 6,079 | 6.06% | |
| 95. | Kenilworth and Southam | West Midlands | 6,574 | 6.16% | |
| 96. | Brentwood and Ongar | East of England | 5,980 | 6.19% | |
| 97. | Stone, Great Wyrley and Penkridge | West Midlands | 5,466 | 6.39% | |
| 98. | Epping Forest | East of England | 5,682 | 6.80% | |
| 99. | Gosport | South East | 6,054 | 6.84% | |
| 100. | Maldon | East of England | 6,906 | 6.93% | |
| 101. | Sussex Weald | South East | 6,842 | 6.96% | |
| 102. | Kingswinford and Staffordshire South | West Midlands | 6,303 | 6.98% | |
| 103. | Berwickshire, Roxburgh and Selkirk | Scotland | 6,599 | 7.09% | |
| 104. | Windsor | South East | 6,457 | 7.14% | |
| 105. | South Holland and the Deepings | East Midlands | 6,856 | 7.46% | |
| 106. | Surrey East | South East | 7,450 | 7.57% | |
| 107. | Thirsk and Malton | Yorkshire and the Humber | 7,550 | 7.58% | |
| 108. | Christchurch | South West | 7,455 | 7.87% | |
| 109. | Runnymede and Weybridge | South East | 7,627 | 7.90% | |
| 110. | Ruislip, Northwood and Pinner | London | 7,581 | 8.05% | |
| 111. | Weald of Kent | South East | 8,422 | 8.30% | |
| 112. | Hertsmere | East of England | 7,992 | 8.32% | |
| 113. | East Grinstead and Uckfield | South East | 8,480 | 8.41% | |
| 114. | Droitwich and Evesham | West Midlands | 8,995 | 9.07% | |
| 115. | Cambridgeshire North East | East of England | 7,189 | 9.18% | |
| 116. | New Forest East | South East | 8,495 | 9.39% | |
| 117. | Rutland and Stamford | East Midlands | 10,394 | 10.70% | |
| 118. | Arundel and South Downs | South East | 12,134 | 11.08% | |
| 119. | Tonbridge | South East | 11,166 | 11.09% | |
| 120. | Harrow East | London | 11,680 | 12.22% | |
| 121. | Richmond and Northallerton | Yorkshire and the Humber | 12,185 | 12.56% |