List of Canadian politicians who have crossed the floor

This is a list of Canadian politicians who have crossed the floor, in that they have changed party affiliation while in office. These are members of Parliament (MPs) unless otherwise noted. MPPs are members of Provincial Parliament of Ontario MNAs are members of the National Assembly of Quebec MHAs are members of the House of Assembly of Newfoundland and Labrador MLAs are members of the Legislative Assembly of other provinces

Pre-confederation 1866: Andrew Rainsford Wetmore, Anti-Confederate in the New Brunswick colonial legislature, joins the Confederation Party after failing to win a desired cabinet post.

1860s September 1, 1868: Stewart Campbell, formerly an Anti-Confederate MP, becomes a Liberal-Conservative member. January 30, 1869: The Anti-Confederate Party, which opposed Nova Scotia joining Confederation, collapses. Members scatter among different parties: Conservative: Alfred William Savary Liberal-Conservative: Archibald McLelan, James Charles McKeagney, Hugh McDonald, Edmund Mortimer McDonald, Joseph Howe, Thomas Coffin and Hugh Cameron Liberal: James William Carmichael, William Henry Chipman, James Fraser Forbes, William Ross, William Hallett Ray, Patrick Power, Independent: Alfred Gilpin Jones October 9, 1869: Richard John Cartwright, formerly a Liberal-Conservative MP, became a Liberal MP after being denied a position in the cabinet.

1870s 1873: Newton LeGayet MacKay leaves the Conservatives for the Liberals. 1874: Samuel McDonnell leaves the Conservatives for the Liberals. 1879: Five Quebec MLAs leave the Quebec Liberals for the Conservatives, causing the government to fall: Alexandre Chauveau Edmund James Flynn Louis Napoléon Fortin Étienne-Théodore Pâquet Ernest Racicot

1880s 1887: Guillaume Amyot leaves the Conservative caucus to sit as a Nationalist. He later changes his designation to Nationalist Conservative.

1910s 1911: Louis-Joseph Papineau, Liberal MP since 1908, re-elected as a Conservative in 1911.

As a result of the Conscription Crisis of 1917, Conservative Prime Minister Sir Robert Borden forms a Union Government in an attempt to win support across party lines. Opposition leader Sir Wilfrid Laurier refuses to support the new government but many of his MPs cross the floor to support the new government either as Unionist or Liberal-Unionist candidates in the Canadian federal election of 1917. Those loyal to Laurier run as Laurier-Liberals. Conversely, a number of Quebec Conservative MPs abandon Borden over the conscription issue and join the Liberals. 1917: Louis-Joseph Papineau leaves the Conservatives to run as a Laurier-Liberal as a result of the Conscription Crisis. 1917: Robert Lorne Richardson, elected in the 1911 election as a Liberal (but previously sitting as variously a Liberal, Independent Liberal, Independent, and Independent Conservative) runs in the 1917 election as a Unionist. 1917: Honoré Achim crosses the floor from the Conservatives to the Liberals over the conscription issue. He does not run for re-election. 1917: William Andrew Charlton leaves the Liberal Party of Canada to run successfully as a Liberal-Unionist in the 1917 election over conscription. 1917: John Gillanders Turriff, who sat as a Liberal since 1891, runs successfully as a Unionist in the 1917 election. 1917: Alphonse Verville, Labour MP since 1906, runs and is re-elected as a Laurier-Liberal in 1917. 1917: Levi Thomson, a Liberal MP since 1904, re-elected as a Unionist in 1917. 1917: Frederick Forsyth Pardee, Liberal MP since 1905, re-elected as a Liberal-Unionist in 1917. 1917: Edward Walter Nesbitt, Liberal MP since 1908, re-elected as a Unionist in 1917. 1917: Hugh Havelock McLean, Liberal MP since 1908, re-elected as a Unionist in 1917. 1917: Thomas MacNutt, Liberal MP since 1908, re-elected as a Unionist in 1917. 1917: Alexander Kenneth Maclean, Liberal MP since 1900, re-elected as a Unionist in 1917. 1917: William Stewart Loggie, Liberal MP since 1904, re-elected as a Unionist in 1917. 1917: Hugh Guthrie, Liberal MP since 1900, re-elected as a Unionist in 1917. 1917: William Stevens Fielding, Liberal MP since 1896, re-elected as a Liberal-Unionist in 1917. 1917: James McCrie Douglas, Liberal since 1909, re-elected as a Unionist in 1917. 1917: Michael Clark, Liberal since 1908, re-elected as a Liberal-Unionist in 1917. 1917: Frank Broadstreet Carvell, Liberal MP since 1900, joins Borden's Cabinet as Minister of Public Works in October 1917 and runs as a Liberal-Unionist in the subsequent election. 1917: William Ashbury Buchanan, Liberal MP since 1911, re-elected as a Unionist in 1917. 1919: Andrew Knox, elected as a Liberal-Unionist in 1917, joins the Progressives in 1919. 1919: George William Andrews, elected as the Liberal-Unionist MP for Winnipeg Centre in 1917, becomes an independent on June 2, 1919, in protest of the government's handling of the Winnipeg General Strike.

1920s 1922: William James Hammell, Progressive MP for Muskoka, joins the Liberal Party. 1925: William George Baker, Saskatchewan Labour MLA, becomes a Labour-Liberal MLA and then later solely a Liberal Party of Saskatchewan MLA in 1938. 1929: Charles Agar, Saskatchewan Progressive MLA, joins Liberal Party of Saskatchewan.

1930s October 14, 1935: Henry Herbert Stevens, Minister of Trade and Commerce in the Conservative government of R.B. Bennett, leaves the party to form the Reconstruction Party of Canada, but then rejoined the Conservatives in 1938.

1950s 1950: Charles Edwin Greenlay, a Manitoba Progressive Conservative, crossed the floor to join Liberal-Progressive government of Douglas Lloyd Campbell. Leaving the party over his pro-coalition stance, Greenlay was made Provincial Secretary and Minister of Labour."MLA Biographies – Deceased". Legislative Assembly of Manitoba. Archived from the original on 2014-03-30. Greenlay and Campbell were also childhood friends and related by marriage. 1952: Tilly Rolston, British Columbia Progressive Conservative MLA, crossed the floor to join the British Columbia Social Credit Party of W.A.C. Bennett. 1955: Ross Thatcher, Co-operative Commonwealth Federation (CCF) MP from Saskatchewan, leaves the party to sit as an independent. He runs as a Liberal in the 1957 election but is defeated. Subsequently, becomes leader of the Liberal Party of Saskatchewan and then Premier of Saskatchewan. 1955: Sam Drover leaves the Liberal Party of Newfoundland and Labrador to become the province's first MHA representing the CCF, losing his seat in the next year's election.

1960s 1962: Failed New Democratic Party (NDP) leadership contender and former CCF leader Hazen Argue crosses the floor to the Liberals. 1963: 13 Social Credit MPs form a new party called Ralliement des créditistes. 1964: Social Credit MPs, Gérard Ouellet and Gérard Girouard leave the Social Credit party to sit as Progressive Conservatives. 1967: Social Credit Party of Canada MP Bud Olson crosses the floor to the Liberals. 1967: René Lévesque, Quebec MLA for Montreal-Laurier, leaves the Quebec Liberal Party to sit as an independent. Lévesque later formed the Mouvement Souveraineté-Association and then the Parti Québécois, on whose ticket he was re-elected in 1976. 1968: Social Credit leader and MP Robert N. Thompson joins the Progressive Conservative Party. 1969: Liberal MP Perry Ryan (Spadina) quits the Liberal Party to sit as an independent because of the Trudeau government's policies on NATO and its decision to recognize the People's Republic of China. In 1970 Ryan joined the Progressive Conservatives, but lost his seat (coming 3rd) in the 1972 federal election.

1970s 1971: Paul Hellyer, left the Liberal caucus to sit as an independent Liberal on May 21, 1971 and subsequently attempted to form a new party, Action Canada. He joined the Progressive Conservatives on July 25, 1972, and sought its leadership in 1976. (In 1982, outside of Parliament and the political spotlight, he rejoined the Liberals, in 1995 formed the Canadian Action Party, and in the 2000s sought to merge it with the NDP.) 1972: Raymond Rock physically crossed the floor from the Liberals caucus to join the Progressive Conservatives on March 13, 1972. 1974: Hugh Curtis, BC Conservative MLA, crossed to Social Credit. 1975: Garde Gardom, Pat McGeer, and Allan Williams, all BC Liberal MLAs, crossed to Social Credit. 1975: Frank Calder, MLA for Atlin since 1949, crossed floor from NDP to Social Credit. 1977: Jack Horner left Progressive Conservatives to join Liberals, ultimately as part of Pierre Trudeau's cabinet. He was defeated as Liberal candidate in 1979. MP Jacques Lavoie representing the riding in Ontario, Hochelaga crossed In June 1977. 1977: Colin Thatcher, Saskatchewan MLA for Thunder Creek, defected from Liberals to the Conservatives. 1978: James Armstrong Richardson leaves the Liberals by physically crossing the floor to sit as an independent MP.

1980s 1980: Thomas Rideout, Liberal Party of Newfoundland and Labrador MHA, crosses the floor to join the Progressive Conservative Party of Newfoundland and Labrador over disputes with the federal government concerning control of offshore mineral resources. 1980: Dick Collver and Dennis Ham leave the Progressive Conservative Party of Saskatchewan to form the Unionest Party, which advocates for the western Provinces to join the United States. Neither sought re-election in 1982, resulting in the disappearance of the Unionest Party. 1982: Peter Ittinuar, MP, leaves New Democrats to join Liberals. 1985: Al Passarell, MLA for Atlin who defeated Frank Calder, crosses from NDP to Social Credit. 1985: Graham Lea, MLA for Prince Rupert, left the NDP after he was badly defeated in the NDP leadership race. He joined the recently formed but short-lived United Party of BC, so then joined the British Columbia Conservative Party becoming its last MLA until John van Dongen crossed from the BC Liberals in 2012. 1986: Gilles Roch, Manitoba Liberal Party MLA, defects to the Progressive Conservative Party of Manitoba after being denied permission to run as a Liberal candidate. 1986: David Ramsay, Ontario MPP, left Ontario New Democratic Party to join Ontario Liberal Party. 1986: Tony Lupusella, Ontario MPP, left Ontario New Democratic Party to join Ontario Liberal Party. 1986: Robert Toupin, MP, leaves the Progressive Conservatives, attempts to sit as a Liberal but is rejected, joining the NDP, before soon after leaving the NDP to sit as an independent.

1990s 1990: Lucien Bouchard, MP, quit the Progressive Conservatives to sit as an independent; with other MPs, he later formed the Bloc Québécois. 1990: David Kilgour, MP, quit the Progressive Conservatives to sit as an independent, then later joined Liberals. In 2005, Kilgour left the Liberal Party to again sit as an independent. 1990: Jean Lapierre, Liberal MP for Shefford, Quebec, leaves Liberal caucus to sit as a member of the Bloc Québécois. Lapierre would eventually return as a Liberal and was elected to the House of Commons in 2004. 1992: Richard Holden, Quebec MNA for Westmount, left the Equality Party to sit as an independent, finally joining Parti Québécois. This move was seen as unusual as the Equality Party, a federalist English-rights party, was the ideological opposite of the PQ. 1993: Dennis Drainville quit the Ontario New Democratic Party caucus to sit as an independent to protest the Rae government's decision to allow casino gambling in the province. 1993: Gordon Wilson and Judi Tyabji, British Columbia MLAs, left British Columbia Liberal Party to found the Progressive Democratic Alliance. 1993: Glen McPherson leaves the New Democratic Party of Saskatchewan and joins the Liberal Party of Saskatchewan.