A by-election was held in the Bermondsey constituency in South London, on 24 February 1983, following the resignation of Labour MP Bob Mellish. Peter Tatchell stood as the candidate for the Labour Party, and Simon Hughes stood for the Liberal Party. Following a bitter campaign, the Liberals made huge gains and took the seat, with a majority of votes cast. Labour's vote fell from 63.6 per cent in May 1979 to 26.1 per cent as Tatchell came a distant second, while the Conservative candidate, Robert Hughes, managed only fourth place, losing his deposit. With a swing of 44.2%, the 1983 Bermondsey by-election remains the largest by-election swing in British political history.

In the 2006 Liberal Democrats leadership election, Sir Menzies Campbell was elected to succeed Charles Kennedy as Leader of the Liberal Democrats, the third-largest political party in the United Kingdom.