All 630 seats in the House of Commons
316 seats needed for a majority
Colours denote the winning party—as shown in § Results
Composition of the House of Commons after the election
Wilson decided to call a snap election since his government, elected a mere 17 months previously, in 1964, had an unworkably small majority of only four MPs. The Labour government was returned following this snap election with a much larger majority of 98 seats. This was the last general election in which the voting age was 21; Wilson's government passed an amendment to the Representation of the People Act in 1969 to include eligibility to vote at age 18, which was in place for the next general election in 1970.
Prior to the 1966 general election, Labour had performed poorly in local elections in 1965, and lost a by-election, cutting their majority to just two. Shortly after the local elections, the leader of the Conservative Party Alec Douglas-Home was replaced by Edward Heath.
The Conservatives had not had much time to prepare their campaign, although it was more professional than previously. There had been little time for Heath to become well known among the British public, having led the party for just eight months before the election. For the Liberals, money was an issue: two elections in the space of just two years had left the party in a tight financial position. Labour ran its campaign with the slogan "You know Labour government works".
The election night was broadcast live on the BBC, was presented by Cliff Michelmore, Ian Trethowan, Robin Day, Robert McKenzie and David Butler. The election was replayed on the BBC Parliament channel on the 40th anniversary of the event, and again in 2016 to mark the 50th anniversary of the election.
Although the BBC's telecast was in black and white, a couple of colour television cameras were placed in the BBC election studio at Television Centre to allow CBS's Charles Collingwood and NBC's David Brinkley to file live reports from that studio by satellite and in colour for their respective networks' evening news programmes (which were transmitted at 11:30 pm British time, 6:30 pm Eastern Standard Time).
|Thursday 10 March||Dissolution of the 43rd Parliament and campaigning officially begins|
|Monday 21 March||Last day to file nomination papers; 1,707 candidates enter to contest 630 seats|
|Wednesday 30 March||Campaigning officially ends|
|Thursday 31 March||Polling day|
|Friday 1 April||The Labour Party wins with an improved majority of 98|
|Monday 18 April||44th Parliament assembles|
|Thursday 21 April||State Opening of Parliament|
|Opinion polling for UK general elections|
|Party||Leader||Stood||Elected||Gained||Unseated||Net||% of total||%||No.||Net %|
|Plaid Cymru||Gwynfor Evans||20||0||0||0||0||0.2||61,071||−0.1|
|Republican Labour||Gerry Fitt||1||1||1||0||+1||0.2||0.1||26,292||0.0|
|British National||John Bean||3||0||0||0||0||0.0||5,182||0.0|
|Union Movement||Oswald Mosley||4||0||0||0||0||0.0||4,075||N/A|
|National Democratic||David Brown||1||0||0||0||0||0.0||769||N/A|
|National Teenage||Screaming Lord Sutch||1||0||0||0||0||0.0||585||N/A|
|Ind. Labour Party||Emrys Thomas||1||0||0||0||0||0.0||441||0.0|
|Radical Alliance||Pat Arrowsmith||1||0||0||0||0||0.0||163||N/A|
|Patriotic Party||Richard Hilton||1||0||0||0||0||0.0||126||0.0|
|Government's new majority||98|
|Total votes cast||27,264,747|
These declarations were covered live by the BBC where the returning officer was heard to say "duly elected".
|Constituency||Winning party 1964||Constituency result 1966 by party||Winning party 1966|
|Wolverhampton North East||Labour||12,965||21,067||Labour hold|
|Wolverhampton South West||Conservative||21,466||14,881||Conservative hold|
|Salford West||Labour||13,257||19,237||Labour hold|
|Salford East||Labour||9,000||18,409||Labour hold|
|Devon North||Liberal||15,631||6,127||16,797||Liberal hold|
|Nelson and Colne||Labour||13,829||18,406||5,117||Labour hold|
|Preston South||Labour||17,931||20,720||Labour hold|
|Brentford and Chiswick||Conservative||14,031||14,638||2,063||Labour gain|
|Aberdeenshire West||Conservative||13,956||6,008||15,151||Liberal gain|