Mitcham and Morden by-election, 1982

The Mitcham and Morden by-election was held on 3 June 1982. It was a rare example of a governing party (the British Conservatives) gaining a seat in a by-election.

The by-election was caused by the resignation of Bruce Douglas-Mann, the Member of Parliament for Mitcham and Morden. Douglas-Mann had retained the seat for the Labour Party since its creation for the February 1974 general election. The constituency had been created from parts of Merton and Morden and Mitcham, both of which had usually generally returned Conservative Party MPs. At the 1979 general election, Douglas-Mann had held the seat with a majority of only 618 votes over the Conservatives.

Douglas-Mann decided in early 1982 to join the recently formed Social Democratic Party (SDP); several other MPs had already joined the party. Although there was no requirement to do so, he decided to resign his seat and stand in the resulting by-election in order to gain a mandate for his change of allegiance.

With a Conservative government in power, their share of the vote might have been expected to decline, but with the Falklands War in progress, their approval ratings were high, and the party hoped to make a decent showing. The party stood Angela Rumbold, a councillor in Kingston-upon-Thames.

The Labour Party was suffering from defections to the SDP, and thought it unlikely that they would hold the seat. They stood David Nicholas.

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