© Richard Kimber
| Constituency | Majority | Majority as % of Total Vote | Majority as % of Electorate | Winning Party | Runner-up |
|---|---|---|---|---|---|
| Llanelli | 21 | 0.09 | 0.04 | Labour | Plaid Cymru |
| Conwy | 72 | 0.34 | 0.13 | Labour | Plaid Cymru |
| Clwyd West | 436 | 1.97 | 0.80 | Labour | Conservative |
| Carmarthen W & Pembrokeshire S | 515 | 2.15 | 0.91 | Labour | Plaid Cymru |
| Cardiff North | 540 | 1.95 | 0.84 | Labour | Conservative |
| Wrexham | 973 | 5.60 | 1.93 | John Marek Ind Party | Labour |
| Preseli Pembrokeshire | 1326 | 5.81 | 2.40 | Labour | Conservative |
| Delyn | 1624 | 9.62 | 2.98 | Labour | Conservative |
| Ynys Mon | 2255 | 8.93 | 4.51 | Plaid Cymru | Conservative |
| Vale of Glamorgan | 2653 | 9.53 | 3.85 | Labour | Conservative |
| Montgomeryshire | 2297 | 11.79 | 5.04 | Liberal Democrat | Conservative |
| Bridgend | 2421 | 10.93 | 3.87 | Labour | Conservative |
| Swansea West | 2562 | 13.20 | 4.36 | Labour | Plaid Cymru |
| Vale of Clwyd | 2769 | 15.48 | 5.61 | Labour | Conservative |
| Clwyd South | 2891 | 15.49 | 5.41 | Labour | Plaid Cymru |
| Newport East | 3464 | 20.27 | 6.12 | Labour | Conservative |
| Alyn & Deeside | 3503 | 23.25 | 5.79 | Labour | Conservative |
| Newport West | 3752 | 17.51 | 6.13 | Labour | Conservative |
| Swansea East | 3997 | 22.96 | 6.98 | Labour | Liberal Democrat |
| Cardiff South & Penarth | 4114 | 20.45 | 6.28 | Labour | Conservative |
| Carmarthen E & Dinefwr | 4614 | 17.24 | 8.53 | Plaid Cymru | Labour |
| Ceredigion | 4618 | 17.55 | 8.72 | Plaid Cymru | Liberal Democrat |
| Neath | 4946 | 22.29 | 8.71 | Labour | Plaid Cymru |
| Caerphilly | 4974 | 19.59 | 7.30 | Labour | Plaid Cymru |
| Brecon & Radnorshire | 5308 | 19.77 | 9.88 | Liberal Democrat | Conservative |
| Gower | 5688 | 24.00 | 9.40 | Labour | Conservative |
| Meirionydd Nant Conwy | 5826 | 38.35 | 17.27 | Plaid Cymru | Labour |
| Caernarfon | 5905 | 27.80 | 12.52 | Plaid Cymru | Labour |
| Ogmore | 6504 | 38.82 | 13.12 | Labour | Plaid Cymru |
| Cardiff West | 6837 | 33.02 | 11.30 | Labour | Conservative |
| Pontypridd | 6920 | 28.36 | 10.95 | Labour | Plaid Cymru |
| Torfaen | 6964 | 35.61 | 11.37 | Labour | Conservative |
| Cynon Valley | 7117 | 42.70 | 16.00 | Labour | Plaid Cymru |
| Cardiff Central | 7156 | 34.74 | 11.46 | Liberal Democrat | Labour |
| Islwyn | 7320 | 35.73 | 14.31 | Labour | Plaid Cymru |
| Aberavon | 7813 | 41.66 | 15.56 | Labour | Plaid Cymru |
| Rhondda | 7954 | 34.58 | 15.76 | Labour | Plaid Cymru |
| Merthyr Tydfil & Rhymney | 8160 | 44.29 | 14.63 | Labour | Plaid Cymru |
| Monmouth | 8510 | 30.62 | 13.63 | Conservative | Labour |
| Blaenau Gwent | 11736 | 59.36 | 22.17 | Labour | Liberal Democrat |
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| Last Modified: 13 Feb 10 © Richard Kimber |