A ministerial by-election was a by-election to fill a vacancy triggered by the appointment of the sitting member of parliament (MP) as a minister in the cabinet. The requirement for new ministers to stand for re-election was introduced in the House of Commons of Great Britain in 1707 and also featured in Westminster system parliaments modelled on it. In latter times, the by-election was usually a formality, uncontested by the opposition. In the United Kingdom, ministerial by-elections were abolished as an anachronism in 1926. The Irish Free State, Union of South Africa, and Dominion of New Zealand never had them.
Ministerial by-elections were a feature of the House of Commons of Great Britain, and its successor the House of Commons of the United Kingdom, from 1707 to 1926. Seventeenth-century English history established the doctrine of parliamentary sovereignty, in particular from interference by the monarch. In 1624, the House of Commons of England resolved that an MP could not resign his seat, and in 1680 it resolved that accepting an office of profit from the Crown would precipitate resignation from the House. Sections 24 and 25 of the Succession to the Crown Act 1707 listed ministerial offices among those considered offices of profit, while mitigating this by allowing the option of standing for re-election. A minister typically sought re-election in the same constituency he had just vacated, but occasionally contested another seat which was also vacant. In 1910 The Times newspaper noted that the relevant Act had been passed in the reign of Queen Anne "to prevent the Court from swamping the House of Commons with placemen and pensioners", and described the process as "anomalous" and "indefensible" in the 20th century. The Reform Act 1867 made cabinet reshuffles easier by abolishing the necessity to seek re-election for an existing minister taking a new portfolio. During the First World War, temporary acts in 1915 and 1916 suspended the requirement for re-election, in order to allow the War Cabinets of the Asquith coalition ministry and the Lloyd George ministry to be appointed quickly. The Re-Election of Ministers Act 1919 ended the requirement within nine months of a general election, and the Re-Election of Ministers Act (1919) Amendment Act 1926, introduced by the opposition as a private member's bill, ended the practice in all other cases.
Ministerial by-elections also occurred in the federal House of Commons of Canada until 1931, and in Canadian provincial assemblies. One controversy within the 1926 King–Byng Affair was prime minister Arthur Meighen's appointment of "acting ministers" to circumvent the need for by-elections. Ministerial by-elections were abolished by the Legislative Assemblies of Alberta in 1926, of Quebec, of New Brunswick, and of Nova Scotia in 1927, of British Columbia in 1929, of Prince Edward Island in 1932, of Saskatchewan in 1936, of Manitoba in 1937, and of Ontario in 1941 (partially in 1926). In addition Newfoundland, at the time a separate Dominion from Canada, abolished Ministerial by-elections in 1928. The North-West Territories also used ministerial by-elections during the period of Responsible Government from 1897–1905.
The legislatures of the British colonies in Australia required ministerial by-elections, though the federal House of Representatives created in 1901 never did. The requirement was abolished in the Queensland Legislative Assembly in 1884, the Tasmanian House of Assembly in 1901, the New South Wales Legislative Assembly in 1906, the Victorian Legislative Assembly in 1915, and the Western Australian Legislative Assembly in 1947.
- Beaven, Alfred B. (1911). "List of opposed elections on taking office". English Historical Review. Longmans, Green. 26 (101): 139–148.
- Cannon, John; W. A. Speck (1978). "Re-election on Taking Office, 1706–90". Historical Research. 51 (124): 206–209. doi:10.1111/j.1468-2281.1978.tb01883.x. ISSN 0950-3471.
- Hawkins, Angus (2013). "Government Appointment By-Elections: 1832–1886". In Otte, T.G.; Readman, Paul. By-Elections in British Politics, 1832–1914. Boydell. ISBN 1843837803.
- Isaacs, Victor (Autumn 2005). "The Case of the Missing Premier — A Strange Parliamentary Practice" (PDF). Australian Parliamentary Review. 20 (1): 34–53.
- Pugh, Martin (2008). "'Queen Anne is dead': The Abolition of Ministerial By-Elections, 1867–1926". Parliamentary History. 21 (3): 351–366. doi:10.1111/j.1750-0206.2002.tb00238.x. ISSN 0264-2824.
- Constitution of the Irish Free State, Article 58 "The appointment of a member of Dáil Eireann to be a Minister shall not entail upon him any obligation to resign his seat or to submit himself for re-election."
- Isaacs 2005, p.40
- Sandford, Mark (18 July 2013). "SN/PC/06395 : Resignation from the House of Commons" (PDF). House of Commons Background Papers. Parliament and Constitution Centre. pp. 1, 4. Retrieved 25 February 2015.
- Isaacs 2005, p.34; Browning, Andrew (1995-12-28). English Historical Documents, 1660-1714. Psychology Press. p. 129. ISBN 9780415143714. Retrieved 27 February 2015.
- Boothroyd, David. "Causes of Byelections since the 'Reform Act'". United Kingdom Election Results. demon.co.uk. Archived from the original on 8 August 2011. Retrieved 25 February 2015.
- "Election Intelligence. Walthamstow., The Osborne Judgment". The Times. 12 October 1910. p. 10. Retrieved 30 August 2012.(subscription required)
- Pugh 2008
- Isaacs 2005, p.36
- "The House of Commons and Its Members - Rules of Membership for the House". House of Commons Procedure and Practice. Parliament of Canada. 2009. Retrieved 25 February 2015.
- Isaacs 2005, pp.39–40
- Smallwood, Joseph R (1981). Encyclopedia of Newfoundland and Labrador. v. 1. p. 717. ISBN 0-920508-14-6.
- Saskatchewan Executive and Legislative Directory: North-West Territories: Council and Legislative Assembly, 1876-1905 |url=http://www.saskarchives.com/sites/default/files/documents/NWT-Council.pdfelections[permanent dead link]
- "Glossary : ministerial by-election". Australian Politics and Elections Database. University of Western Australia. Retrieved 26 February 2015.