What is a parliamentary by-election?
A parliamentary by-election is called if a casual vacancy arises in the House of Commons because of the death, resignation, or elevation to the House of Lords of an MP between general elections. Parliamentary by-elections cannot normally affect the balance of power in the House of Commons, unless the Government’s majority is very small (e.g. Wilson’s Labour Government, 1964-6, Wilson’s and Callaghan’s Governments 1974-9, or Major’s Conservative Government 1992-7). Turnout is often appreciably lower than for the same constituency in a General Election. Voting behaviour may be more volatile. Commonly, voters use by-elections to vent their grievances against the government of the day. Sometimes the official opposition is the beneficiary, but the Liberals and their more recent successors, the Liberal Democrats, and sometimes nationalists have sometimes recorded sensational victories. The personalities of party candidates usually count for more than in General Elections, and local issues ca
