This is a list of marginal seats in the United Kingdom after the results in the 2010 General Election.
Most marginal constituencies
Ten most marginal seats (by majority) from 2010 General Election.
| Rank | Constituency | MP Elected | First Party | Second Party | Majority | % |
| 1 | Fermanagh and South Tyrone | Michelle Gildernew | Sinn Féin | Independent | 4 | 0.0% |
| 2 | Hampstead and Kilburn | Glenda Jackson | Labour | Conservative | 42 | 0.1% |
| 3 | North Warwickshire | Daniel Byles | Conservative | Labour | 54 | 0.1% |
| 4 | Camborne and Redruth | George Eustice | Conservative | Liberal Democrat | 66 | 0.2% |
| 5 | Bolton West | Julie Hilling | Labour | Conservative | 92 | 0.2% |
| 5 | Thurrock | Jackie Doyle-Price | Conservative | Labour | 92 | 0.2% |
| 7 | Oldham East and Saddleworth* | Phil Woolas | Labour | Liberal Democrat | 103 | 0.2% |
| 8 | Hendon | Matthew Offord | Conservative | Labour | 106 | 0.2% |
| 9 | Sheffield Central | Paul Blomfield | Labour | Liberal Democrat | 165 | 0.4% |
| 10 | Solihull | Lorely Burt | Liberal Democrat | Conservative | 175 | 0.3% |
Conservative marginals
Conservative - Labour marginals
Constituencies where the Conservative Party holds a marginal lead over the Labour Party:
| Constituency | MP Elected | Majority | % |
| North Warwickshire | Daniel Byles | 54 | 0.1% |
| Thurrock | Jackie Doyle-Price | 92 | 0.2% |
| Hendon | Matthew Offord | 106 | 0.2% |
| Cardiff North | Jonathan Evans | 194 | 0.4% |
| Sherwood | Mark Spencer | 214 | 0.4% |
| Stockton South | James Wharton | 332 | 0.7% |
| Lancaster and Fleetwood | Eric Ollerenshaw | 333 | 0.8% |
| Broxtowe | Anna Soubry | 389 | 0.7% |
| Amber Valley | Nigel Mills | 536 | 1.2% |
| Wolverhampton South West | Paul Uppal | 691 | 1.7% |
| Waveney | Peter Aldous | 769 | 1.5% |
| Carlisle | John Stevenson | 853 | 2.0% |
| Morecambe and Lunesdale | David Morris | 866 | 2.0% |
| Weaver Vale | Graham Evans | 991 | 2.3% |
| Lincoln | Karl McCartney | 1,058 | 2.3% |
| Plymouth, Sutton and Devonport | Oliver Colvile | 1,149 | 2.6% |
| Stroud | Neil Carmichael | 1,299 | 2.2% |
| Brighton, Kemptown | Simon Kirby | 1,328 | 3.1% |
| Bedford | Richard Fuller | 1,353 | 3.0% |
| Dewsbury | Simon Reevell | 1,526 | 2.8% |
| Keighley | Kris Hopkins | 2,940 | 6.2% |
| Worcester | Robin Walker | 2,982 | 6.1% |
| Cannock Chase | Aidan Burley | 3,195 | 7.0% |
| Aberconwy | Guto Bebb | 3,398 | 11.3% |
| Harrow East | Bob Blackman | 3,403 | 7.1% |
| Carmarthen West and South Pembrokeshire | Simon Hart | 3,423 | 8.5% |
| Warwick and Leamington | Chris White | 3,513 | 7.2% |
| South Swindon | Robert Buckland | 3,544 | 7.5% |
| Stevenage | Stephen McPartland | 3,578 | 8.0% |
| Pendle | Andrew Stephenson | 3,585 | 8.0% |
| Ealing Central and Acton | Angie Bray | 3,716 | 7.9% |
| Loughborough | Nicky Morgan | 3,744 | 7.1% |
| Dudley South | Chris Kelly | 3,856 | 10.1% |
| Norwich North | Chloe Smith | 3,901 | 9.2% |
| Dumfriesshire, Clydesdale and Tweeddale | David Mundell | 4,194 | 9.1% |
| Great Yarmouth | Brandon Lewis | 4,276 | 9.9% |
| Cleethorpes | Martin Vickers | 4,298 | 9.6% |
| Vale of Glamorgan | Alun Cairns | 4,307 | 8.8% |
| Rossendale and Darwen | Jake Berry | 4,493 | 9.5% |
| Elmet and Rothwell | Alec Shelbrooke | 4,521 | 8.1% |
| Preseli Pembrokeshire | Stephen Crabb | 4,605 | 11.6% |
| High Peak | Andrew Bingham | 4,677 | 9.3% |
| Peterborough | Stewart Jackson | 4,861 | 10.8% |
| North East Somerset | Jacob Rees-Mogg | 4,914 | 9.6% |
| Harlow | Robert Halfon | 4,925 | 11.2% |
Conservative - Liberal Democrat marginals
Constituencies where the Conservative Party holds a marginal lead over the Liberal Democrats:
| Constituency | MP Elected | Majority | % |
| Camborne and Redruth | George Eustice | 66 | 0.2% |
| Oxford West and Abingdon | Nicola Blackwood | 176 | 0.3% |
| Truro and Falmouth | Sarah Newton | 435 | 0.9% |
| Newton Abbot | Anne Morris | 523 | 1.1% |
| Harrogate and Knaresborough | Andrew Jones | 1,039 | 2.0% |
| Montgomeryshire | Glyn Davies | 1,184 | 3.5% |
| Watford | Richard Harrington | 1,425 | 2.6% |
| St Albans | Anne Main | 2,305 | 4.4% |
| Hereford and South Herefordshire | Jesse Norman | 2,481 | 5.1% |
| Weston-super-Mare | John Penrose | 2,691 | 5.1% |
| Torridge and West Devon | Geoffrey Cox | 2,957 | 5.4% |
| Winchester | Steve Brine | 3,048 | 5.4% |
| South East Cornwall | Sheryll Murray | 3,220 | 6.5% |
| Bristol North West | Charlotte Leslie | 3,274 | 6.5% |
| York Outer | Julian Sturdy | 3,688 | 6.9% |
| West Dorset | Oliver Letwin | 3,923 | 6.8% |
| Richmond Park | Zac Goldsmith | 4,091 | 6.9% |
| Romsey and Southampton North | Caroline Nokes | 4,156 | 8.5% |
| Colne Valley | Jason McCartney | 4,837 | 8.7% |
| Totnes | Sarah Wollaston | 4,927 | 10.3% |
Other Conservative marginals
Constituencies where the Conservative Party holds a marginal lead over another party:
| Constituency | MP Elected | First Party | Second Party | Majority | % |
| Wyre Forest | Mark Garnier | Conservative | Health Concern | 2,643 | 5.2% |
Liberal Democrat marginals
Liberal Democrat - Conservative marginals
Constituencies where the Liberal Democrats holds a marginal lead over the Conservative Party:
| Constituency | MP Elected | Majority | % |
| Solihull | Lorely Burt | 175 | 0.3% |
| Mid Dorset and North Poole | Annette Brooke | 269 | 0.6% |
| Wells | Tessa Munt | 800 | 1.4% |
| St Austell and Newquay | Stephen Gilbert | 1,312 | 2.8% |
| Sutton and Cheam | Paul Burstow | 1,608 | 3.3% |
| St Ives | Andrew George | 1,719 | 3.7% |
| Somerton and Frome | David Heath | 1,817 | 3.0% |
| Chippenham | Duncan Hames | 2,470 | 4.7% |
| Berwick-upon-Tweed | Alan Beith | 2,690 | 7.0% |
| North Cornwall | Dan Rogerson | 2,981 | 6.4% |
| Cheadle | Mark Hunter | 3,272 | 6.2% |
| Argyll and Bute | Alan Reid | 3,431 | 7.6% |
| Eastbourne | Stephen Lloyd | 3,435 | 6.6% |
| West Aberdeenshire and Kincardine | Robert Smith | 3,684 | 8.2% |
| Brecon and Radnorshire | Roger Williams | 3,747 | 9.6% |
| Eastleigh | Chris Huhne | 3,864 | 7.2% |
| Taunton Deane | Jeremy Browne | 3,993 | 6.9% |
| Torbay | Adrian Sanders | 4,078 | 8.3% |
| Cheltenham | Martin Horwood | 4,920 | 9.3% |
Liberal Democrat - Labour marginals
Constituencies where the Liberal Democrats holds a marginal lead over the Labour Party:
| Constituency | MP Elected | Majority | % |
| Norwich South | Simon Wright | 310 | 0.7% |
| Bradford East | David Ward | 365 | 0.9% |
| Brent Central | Sarah Teather | 1,345 | 3.0% |
| Burnley | Gordon Birtwistle | 1,818 | 4.3% |
| Manchester, Withington | John Leech | 1,894 | 4.2% |
| East Dunbartonshire | Jo Swinson | 2,184 | 4.6% |
| Birmingham, Yardley | John Hemming | 3,002 | 7.3% |
| Edinburgh West | Mike Crockart | 3,803 | 8.2% |
| Cardiff Central | Jenny Willott | 4,576 | 12.7% |
| Caithness, Sutherland and Easter Ross | John Thurso | 4,826 | 16.8% |
Labour marginals
Labour - Conservative marginals
Constituencies where the Labour Party holds a marginal lead over the Conservative Party:
| Constituency | MP Elected | Majority | % |
| Hampstead and Kilburn | Glenda Jackson | 42 | 0.1% |
| Bolton West | Julie Hilling | 92 | 0.2% |
| Southampton, Itchen | John Denham | 192 | 0.4% |
| Wirral South | Alison McGovern | 531 | 1.3% |
| Derby North | Chris Williamson | 613 | 1.4% |
| Dudley North | Ian Austin | 649 | 1.7% |
| Great Grimsby | Austin Mitchell | 714 | 2.2% |
| Telford | David Wright | 978 | 2.4% |
| Walsall North | David Winnick | 990 | 2.7% |
| Morley and Outwood | Ed Balls | 1,101 | 2.3% |
| Birmingham, Edgbaston | Gisela Stuart | 1,274 | 3.1% |
| Halifax | Linda Riordan | 1,472 | 3.4% |
| Newcastle-under-Lyme | Paul Farrelly | 1,552 | 3.6% |
| Plymouth, Moor View | Alison Seabeck | 1,588 | 3.8% |
| Wakefield | Mary Creagh | 1,613 | 3.6% |
| Eltham | Clive Efford | 1,663 | 4.0% |
| Middlesbrough South and East Cleveland | Tom Blenkinsop | 1,677 | 3.6% |
| Walsall South | Valerie Vaz | 1,755 | 4.3% |
| Nottingham South | Lilian Greenwood | 1,772 | 4.3% |
| Blackpool South | Gordon Marsden | 1,852 | 5.3% |
| Gedling | Vernon Coaker | 1,859 | 3.9% |
| Westminster North | Karen Buck | 2,126 | 5.4% |
| Bridgend | Madeleine Moon | 2,263 | 5.9% |
| Delyn | David Hanson | 2,272 | 6.1% |
| Luton South | Gavin Shuker | 2,329 | 5.5% |
| Southampton, Test | Alan Whitehead | 2,413 | 5.5% |
| North East Derbyshire | Natascha Engel | 2,445 | 5.2% |
| Wolverhampton North East | Emma Reynolds | 2,484 | 7.1% |
| Vale of Clwyd | Chris Ruane | 2,509 | 7.1% |
| Tooting | Sadiq Khan | 2,524 | 5.0% |
| Scunthorpe | Nick Dakin | 2,549 | 6.9% |
| Chorley | Lindsay Hoyle | 2,593 | 5.2% |
| Dagenham and Rainham | Jon Cruddas | 2,630 | 5.9% |
| Gower | Martin Caton | 2,683 | 6.4% |
| Exeter | Ben Bradshaw | 2,721 | 5.2% |
| Stalybridge and Hyde | Jonathan Reynolds | 2,744 | 6.7% |
| Birmingham, Northfield | Richard Burden | 2,782 | 6.7% |
| Clwyd South | Susan Jones | 2,834 | 8.2% |
| Alyn and Deeside | Mark Tami | 2,919 | 7.3% |
| Penistone and Stocksbridge | Angela Smith | 3,049 | 6.6% |
| Hyndburn | Graham Jones | 3,090 | 7.2% |
| Harrow West | Gareth Thomas | 3,143 | 6.8% |
| Birmingham, Erdington | Jack Dromey | 3,277 | 9.2% |
| Bury South | Ivan Lewis | 3,292 | 6.8% |
| Darlington | Jenny Chapman | 3,388 | 7.9% |
| Birmingham, Selly Oak | Stephen McCabe | 3,482 | 7.5% |
| Newport West | Paul Flynn | 3,544 | 8.9% |
| Hammersmith | Andy Slaughter | 3,549 | 7.5% |
| Don Valley | Caroline Flint | 3,595 | 8.3% |
| Bristol East | Kerry McCarthy | 3,722 | 8.3% |
| Copeland | Jamie Reed | 3,833 | 9.0% |
| Coventry South | Jim Cunningham | 3,845 | 8.4% |
| Sefton Central | Bill Esterson | 3,862 | 8.0% |
| Leicester West | Liz Kendall | 4,017 | 11.2% |
| Bolton North East | David Crausby | 4,084 | 9.4% |
| Stoke-on-Trent South | Robert Flello | 4,130 | 10.4% |
| Ellesmere Port and Neston | Andrew Miller | 4,331 | 9.8% |
| Worsley and Eccles South | Barbara Keeley | 4,337 | 10.4% |
| West Lancashire | Rosie Cooper | 4,343 | 9.0% |
| Batley and Spen | Mike Wood | 4,406 | 8.6% |
| Huddersfield | Barry Sheerman | 4,472 | 11.0% |
| Leeds North East | Fabian Hamilton | 4,545 | 9.6% |
| Workington | Tony Cunningham | 4,575 | 11.7% |
| Bradford South | Gerry Sutcliffe | 4,622 | 12.2% |
| Feltham and Heston* | Alan Keen | 4,658 | 9.6% |
| Cardiff South and Penarth* | Alun Michael | 4,709 | 10.6% |
| Cardiff West | Kevin Brennan | 4,751 | 11.6% |
Labour - Liberal Democrat marginals
Constituencies where the Labour Party holds a marginal lead over the Liberal Democrats:
| Constituency | MP Elected | Majority | % |
| Oldham East and Saddleworth* | Phil Woolas | 103 | 0.2% |
| Sheffield Central | Paul Blomfield | 165 | 0.4% |
| Ashfield | Gloria De Piero | 192 | 0.4% |
| Edinburgh South | Ian Murray | 316 | 0.7% |
| Swansea West | Geraint | 504 | 1.4% |
| Chesterfield | Toby Perkins | 549 | 1.2% |
| Kingston upon Hull North | Diana Johnson | 641 | 1.9% |
| Rochdale | Simon Danczuk | 889 | 1.9% |
| Newport East | Jessica Morden | 1,650 | 4.8% |
| Edinburgh North and Leith | Mark Lazarowicz | 1,724 | 3.6% |
| Pontypridd | Owen Smith | 2,785 | 7.6% |
| City of Durham | Roberta Blackman-Woods | 3,067 | 6.6% |
| Streatham | Chuka Umunna | 3,259 | 7.0% |
| Newcastle upon Tyne North | Catherine McKinnell | 3,414 | 7.8% |
| Aberdeen South | Anne Begg | 3,506 | 8.1% |
| Islington South and Finsbury | Emily Thornberry | 3,569 | 8.2% |
| Wrexham | Ian Lucas | 3,658 | 11.1% |
| Glasgow North | Ann McKechin | 3,898 | 13.2% |
| Merthyr Tydfil and Rhymney | Dai Havard | 4,056 | 12.6% |
| Newcastle upon Tyne East | Nicholas Brown | 4,453 | 11.8% |
| Oxford East | Andrew Smith | 4,581 | 8.9% |
| Bristol South | Dawn Primarolo | 4,734 | 9.8% |
Other Labour marginals
Constituencies where the Labour Party holds a marginal lead over another party:
| Constituency | MP Elected | First Party | Second Party | Majority | % |
| Ynys Môn | Albert Owen | Labour | Plaid Cymru | 2,461 | 7.1% |
| Birmingham, Hall Green | Roger Godsiff | Labour | Respect | 3,799 | 7.8% |
| Llanelli | Nia Griffith | Labour | Plaid Cymru | 4,701 | 12.5% |
Other Parties
Other Parties marginal seats by majority:
Alliance Party
| Constituency | MP Elected | First Party | Second Party | Majority | % |
| Belfast East | Naomi Long | Alliance | DUP | 1,533 | 4.4% |
Democratic Unionist Party
| Constituency | MP Elected | First Party | Second Party | Majority | % |
| South Antrim | William McCrea | DUP | UCU | 1,183 | 3.5% |
| Belfast North | Nigel Dodds | DUP | Sinn Féin | 2,224 | 6.0% |
| Upper Bann | David Simpson | DUP | UCU | 3,361 | 8.1% |
Green Party
| Constituency | MP Elected | First Party | Second Party | Majority | % |
| Brighton, Pavilion | Caroline Lucas | Green | Labour | 1,252 | 2.4% |
Plaid Cymru
| Constituency | MP Elected | First Party | Second Party | Majority | % |
| Arfon | Hywel Williams | Plaid Cymru | Labour | 1,455 | 5.6% |
| Carmarthen East and Dinefwr | Jonathan Edwards | Plaid Cymru | Labour | 3,481 | 9.2% |
Social Democratic Labour Party
| Constituency | MP Elected | First Party | Second Party | Majority | % |
| Foyle | Mark Durkan | SDLP | Sinn Féin | 4,824 | 12.7% |
Sinn Fein
| Constituency | MP Elected | First Party | Second Party | Majority | % |
| Fermanagh and South Tyrone | Michelle Gildernew | Sinn Féin | Independent | 4 | 0.0% |
Scottish National Party
| Constituency | MP Elected | First Party | Second Party | Majority | % |
| Dundee East | Stewart Hosie | SNP | Labour | 1,821 | 4.5% |
| Na h-Eileanan an Iar | Angus MacNeil | SNP | Labour | 1,885 | 12.8% |
| Angus | Mike Weir | SNP | Conservative | 3,282 | 8.6% |
| Banff and Buchan | Eilidh Whiteford | SNP | Conservative | 4,027 | 10.5% |
| Perth and North Perthshire | Pete Wishart | SNP | Conservative | 4,379 | 9.1% |
