Although generally popular, the Conservative administration of Harold Macmillan had been hit by differences over economic policy, and in January 1958, all the Government's Treasury Ministers had resigned.
The Liberal Party had reached its lowest ebb in the 1951 general election, winning just 2.5% of the vote nationally, and gaining only six MPs. They had been reduced to five seats when they lost the 1957 Carmarthen by-election, but their fortunes had shown signs of a revival when they came a close second in North Dorset later in the year, and Rochdale early in 1958.
The by-election was held on 27 March 1958. Following Granada Television's screening of the Rochdale by-election earlier in the year, BBC Television chose Torrington for their second recorded election broadcast (after the 1955 general election). When the votes were counted, Bonham-Carter won a surprise victory, by just 219 votes - their first by-election victory since Middlesbrough West in 1945, and that achieved due to the war-time electoral pact. The Conservatives were beaten into second place, while Labour also lost votes and finished third.
For the Liberals there was a somewhat ironic situation. The previous year they had lost a seat to Lloyd George's daughter. Now they had gained a seat with Asquith's grandson.
Bonham-Carter lost the seat less than eighteen months later, in the 1959 general election, and failed to retake it when he stood again in 1964. In 1959, Royle chose to fight Richmond instead, winning a seat in the Commons. The Torrington by-election proved the first Liberal success in a long revival which continued with the 1962 Orpington by-election.