The UK general election in 1966 was called by Harold Wilson because his government, elected in the 1964 election, had an unworkably small majority. Wilson's hope, that he would be returned to office with an increased majority, was excited by the government's victory in a by-election at Kingston upon Hull and was vindicated when the results were as follows -

PartyVotesShareMPs
Labour12,969,28147.57%364
Conservative10,881,32139.91%253
Liberal2,235,4038.62%9
Ulster Unionist Party368,6291.35%11
others1

Harold Wilson's government was able to survive. The 'other' was Gerry Fitt, standing under the Republican Labour Party banner.