# Social Democratic Party election results

The Social Democratic Party was a centre-left to centrist political party in the United Kingdom. It was formed in 1981 and was dissolved in 1988 when it merged with the Liberal Party to form Liberal Democrats.
This article encompasses results of historical UK general elections and European Parliament elections which the Social Democratic Party participated in.

## Westminster elections
### Summary of UK general election performance

| Year | Year | No. of Candidates | Total votes | Mean votes per candidate | % UK vote | Change % +/- | Saved deposits | No. of MPs |
| | 1983 | 311 | 3,570,834 | 11,482 | 11.7% | New | — | 6 |
| | 1987 | 306 | 3,168,183 | 10,354 | 9.7% | 1.9% | — | 5 |

### Parliamentary by-elections, 1981–1983

Through by-elections during the 1979–1983 UK Parliament, the SDP succeeded in electing 2 Social Democrat MPs.
SPD results in Parliamentary by-elections from 1981 to 1983 :
| Election | Candidate | Votes | % | Position | 1979 | 1979 | 1979 | 1979 | Result | By-election | By-election | By-election | By-election |
| Election | Candidate | Votes | % | Position | LAB | LIB | CON | OTH | Result | LAB | SDP | CON | OTH |
| 1981 Warrington by-election | Roy Jenkins | 12,521 | 42.40 | 2 | 61.6 | 9.1 | 28.8 | 9.6 | LAB hold | 48.4 | 42.4 | 7.1 | 2.1 |
| 1981 Crosby by-election | Shirley Williams | 28,118 | 49.0 | 1 | 25.4 | 15.2 | 57.0 | 2.4 | SDP gain from CON | 9.5 | 49.1 | 39.8 | 1.6 |
| 1982 Glasgow Hillhead by-election | Roy Jenkins | 10,106 | 33.40 | 1 | 34.4 | 14.4 | 41.0 | 10.1 | SDP gain from CON | 25.9 | 33.4 | 26.6 | 14.1 |
| 1982 Mitcham and Morden by-election | Bruce Douglas-Mann | 9,032 | 29.40 | 2 | 45.2 | 8.9 | 43.9 | 2.0 | CON gain from LAB | 24.4 | 29.4 | 43.4 | 2.8 |
| 1982 Gower by-election | Gwynoro Jones | 9,875 | 25.10 | 2 | 53.2 | 9.1 | 30.6 | 7.2 | LAB hold | 43.5 | 25.1 | 22.1 | 9.3 |
| 1982 Peckham by-election | Dick Taverne | 7,418 | 32.91 | 2 | 59.9 | 7.7 | 28.1 | | LAB hold | 50.3 | 32.9 | 12.4 | 4.4 |
| 1983 Darlington by-election | Anthony Cook | 12,735 | 24.5 | 3 | 45.6 | 10.2 | 43.4 | 0.9 | LAB hold | 39.5 | 24.5 | 34.9 | 1.1 |

### General election 1983

SPD results in the 1983 general election :
| Constituency | Candidate | Votes | % | Position | Result |
| Aberdeen North | Colin Stirling Deans | 10,118 | 24.7 | 2nd | LAB hold |
| Aberdeen South | Ian Philip | 10,372 | 26.2 | 3rd | CON hold, but SDP and LAB together outpolled them |
| Aldridge-Brownhills | Peter Gunn | 11,599 | 24.4 | 3rd | CON hold |
| Alyn and Deeside | Eric Cyril Hammersley Owen | 9,535 | 21.6 | 3rd | LAB win (new seat) |
| Angus East | Pauline Mary Hammond | 4,978 | 11.4 | 3rd | CON win (new seat) |
| Ashford | Jo Hawkes | 13,319 | 27.8 | 2nd | CON hold |
| Ashton-under-Lyne | John Adler | 7,521 | 17.8 | 3rd | LAB hold |
| Aylesbury | Michael Alexander Soole | 15,310 | 29.4 | 2nd | CON hold |
| Banbury | Keith Fitchett | 13,200 | 26.9 | 2nd | CON hold |
| Banff and Buchan | Edward Allport Needham | 6,084 | 15.0 | 3rd | CON win (new seat) |
| Barnsley West and Penistone | John Evans | 9,624 | 21.7 | 3rd | LAB hold |
| Barrow and Furness | David Cottier | 11,079 | 21.7 | 3rd | SDP split left-wing vote allowing CON gain from LAB |
| Basildon | Sue Slipman | 11,634 | 25.7 | 3rd | CON hold, but SDP and LAB together outpolled them |
| Basingstoke | Ednyfed Hudson Davies (defecting Labour MP from Caerphilly) | 15,931 | 28.8 | 2nd | CON hold |
| Bassetlaw | Brian Withnall | 8,124 | 16.7 | 3rd | LAB hold |
| Bath | Malcolm Dean | 17,240 | 36.0 | 2nd | CON hold, but SDP and LAB together outpolled them |
| Batley and Spen | Stephen Woollery | 11,678 | 21.6 | 3rd | CON win (new seat), but SDP+LAB outpolled them |
| Battersea | M. Harris | 7,675 | 17.5 | 3rd | LAB win (new seat) |
| South West Bedfordshire | Richard Byfield | 16,036 | 27.8 | 2nd | |
| East Berkshire | Kevin Patrick O'Sullivan | 17,868 | 29.9 | 2nd | |
| Birmingham Edgbaston | Joseph Christopher Binns | 8,167 | 22.4 | 2nd | |
| Birmingham Erdington | Christopher Bernard Barber | 7,915 | 21.1 | 3rd | |
| Birmingham Selly Oak | Kevin William Wheldall | 10,613 | 20.7 | 3rd | |
| Birmingham Small Heath | Andrew Bostock | 5,722 | 16.0 | 3rd | |
| Birmingham Sparkbrook | Omkar Singh Parmar | 3,416 | 10.4 | 3rd | |
| Birmingham Yardley | David Anthony Bennett | 8,109 | 23.1 | 3rd | |
| Blackburn | Eric Fairbrother | 8,174 | 14.4 | 3rd | |
| Blackpool South | Alex G. Cox | 9,417 | 24.0 | 3rd | |
| Blaydon | Maurice Carr | 12,607 | 26.3 | 3rd | |
| Blyth Valley | Rosemary Margaret Brownlow | 13,340 | 31.8 | 2nd | |
| Bolsover | S. Reddish | 7,886 | 16.8 | 3rd | |
| Bolton North East | John Alcock | 8,311 | 18.3 | 3rd | |
| Bradford North | Peter Birkby | 11,962 | 25.5 | 3rd | |
| Bradford West | Edward Lyons (defecting Labour MP) | 13,301 | 27.1 | 3rd | LAB hold (that is, reverted to 1979 status quo) |
| Caithness and Sutherland | Robert Maclennan (defecting Labour MP) | 12,119 | 52.0 | 1st | SDP gain from LAB (held 1981 gain) |
| Cannock and Burntwood | Joseph Withnall | 11,336 | 22.1 | 3rd | |
| Cardiff West | Jeffrey Thomas (defecting Labour MP from Abertillery) | 10,388 | 25.5 | 3rd | SDP split left-wing vote allowing CON gain from LAB |
| Clwyd South West | Tom Ellis (defecting Labour MP from Wrexham) | 13,024 | 30.2 | 2nd | CON win in new seat; SDP+LAB together outpolled them |
| Crosby | Shirley Williams (sitting SDP MP) | 27,203 | 42.0 | 2nd | CON hold (that is, reverted to 1979 status quo) |
| Darlington | Ray Dutton | 8,737 | 17.4 | 3rd | |
| Dewsbury | David Ginsburg (defecting Labour MP) | 13,065 | 25.3 | 3rd | SDP split left-wing vote allowing CON gain from LAB |
| Erith and Crayford | James Wellbeloved (defecting Labour MP) | 14,369 | 34.9 | 2nd | SDP split left-wing vote allowing CON gain from LAB |
| Glasgow Hillhead | Roy Jenkins (sitting SDP MP) | 14,856 | 36.2 | 1st | SDP gain from CON (held 1982 by-election gain) |
| Hackney South and Shoreditch | Ronald Brown (defecting Labour MP) | 7,025 | 18.3 | 3rd | LAB hold (that is, reverted to 1979 status quo) |
| Halifax | F. Cockroft | 11,868 | 21.7 | 3rd | |
| Hayes and Harlington | Neville Sandelson (defecting Labour MP) | 11,842 | 29.0 | 3rd | SDP split left-wing vote allowing CON gain from LAB |
| Hyndburn | John Bridgen | 6,716 | 14.6 | 3rd | |
| Islington North | John Grant (defecting Labour MP from abolished Islington Central) | 8,268 | 22.4 | 3rd | LAB hold (that is, reverted to 1979 status quo) |
| Islington South and Finsbury | George Cunningham (defecting Labour MP) | 13,097 | 35.3 | 2nd | LAB hold (that is, reverted to 1979 status quo) |
| Leicester East | Tom Bradley (defecting Labour MP) | 10,362 | 21.1 | 3rd | SDP split left-wing vote allowing CON gain from LAB |
| Lewisham East | Polly Toynbee | 9,351 | 22.0 | 3rd | |
| Leyton | Bryan Magee (defecting Labour MP) | 9,448 | 24.9 | 3rd | LAB hold (that is, reverted to 1979 status quo) |
| Liverpool Broadgreen | Richard Crawshaw (defecting Labour MP from abolished Liverpool Toxteth) | 5,169 | 11.2 | 4th | LAB win in new seat |
| Liverpool West Derby | Eric Ogden (defecting Labour MP) | 7,871 | 18.0 | 3rd | LAB hold (that is, reverted to 1979 status quo) |
| Meriden | Pamela Dunbar | 10,674 | 20.1 | 3rd | |
| Newcastle Central | John Horam (defecting Labour MP from abolished Gateshead West) | 9,923 | 22.3 | 3rd | SDP split left-wing vote allowing CON gain from LAB |
| Newcastle upon Tyne East | Mike Thomas (defecting Labour MP) | 11,293 | 26.7 | 3rd | LAB hold (that is, reverted to 1979 status quo) |
| Newham North West | Alec Kellaway | 5,204 | 18.6 | 3rd | |
| North West Norfolk | Christopher Brocklebank-Fowler (defecting Conservative MP) | 20,211 | 37.6 | 2nd | CON hold, but SDP and LAB together outpolled them |
| Norwich South | Charles Hardie | 11,968 | 24.5 | 3rd | |
| Plymouth Devonport | David Owen (defecting Labour MP) | 20,843 | 44.3 | 1st | SDP gain from LAB (held 1981 gain) |
| Renfrew West and Inverclyde (replaced West Renfrewshire) | Dickson Mabon (defecting Labour MP from abolished Greenock & Port Glasgow) | 12,347 | 29.5 | 2nd | SDP split left-wing vote allowing CON gain from LAB |
| Ross, Cromarty and Skye (replaced Ross and Cromarty) | Charles Kennedy | 13,528 | 38.5 | 1st | SDP gain from CON |
| Slough | Nicholas Bosanquet | 9,519 | 18.5 | 3rd | |
| Southampton Itchen | Bob Mitchell (defecting Labour MP) | 16,647 | 31.5 | 2nd | SDP split left-wing vote allowing CON gain from LAB |
| Stockport | Thomas McNally (defecting Labour MP from abolished Stockport South) | 12,129 | 27.6 | 3rd | SDP split left-wing vote allowing CON win in new seat |
| Stockton North (replaced Stockton-on-Tees) | William Rodgers (defecting Labour MP) | 14,630 | 29.6 | 3rd | LAB hold (that is, reverted to 1979 status quo) |
| Stockton South (replaced Thornaby) | Ian Wrigglesworth (defecting Labour MP) | 19,550 | 36.8 | 1st | SDP gain from LAB (held 1981 gain) |
| Woolwich (replaced Woolwich East) | John Cartwright (defecting Labour MP) | 15,492 | 40.5 | 1st | SDP gain from LAB (held 1981 gain) |
| Worsley | John Roper (defecting Labour MP from Farnworth) | 14,545 | 27.1 | 3rd | LAB win in new seat |

### Parliamentary by-elections, 1983–1987

Through by-elections during the 1983–1987 UK Parliament, the SDP succeeded in electing 2 Social Democrat MPs.

## Local elections

The SDP participated in the 1982, 1983, 1984, 1985, 1986, 1987 local elections.

## European Parliament elections

| Year | Year | No. of Candidates | Total votes | % UK vote | No. of MEPs |
| | 1984 | | 1,233,490 | 9.0 | 0 |