What is floor crossing in the Canadian Parliament?

Floor crossing is the term for when a Member of Parliament leaves their party's caucus to join another party or to sit as an independent MP. Floor crossing is constitutionally permitted under Canadian law: MPs are elected as individuals (not as party representatives), and the Constitution Act, 1867 does not require them to remain with the party they were elected with. Floor crossing has occurred frequently in Canadian history but remains controversial, particularly when it shifts the balance of a minority Parliament.

Notable floor crossings include Lucien Bouchard's 1990 departure from the Progressive Conservative caucus (in protest over the Meech Lake Accord collapse) to found the Bloc Québécois with other PC and Liberal MPs; David Emerson's February 6, 2006 crossing from the Liberals to the Conservatives (immediately after the federal election in which he had been elected as a Liberal, joining Stephen Harper's Cabinet as Minister of International Trade); Belinda Stronach's May 17, 2005 crossing from the Conservatives to the Liberals (giving Paul Martin's minority government a critical additional vote that helped it survive a May 2005 confidence vote); and Garth Turner's 2006 expulsion from the Conservative caucus and subsequent move to the Liberals.

More recent floor crossings include Eve Adams's February 9, 2015 move from the Conservatives to the Liberals (with Justin Trudeau's invitation, though she lost the Liberal nomination contest for her riding), Jane Philpott's and Jody Wilson-Raybould's April 2, 2019 expulsion from the Liberal caucus (over the SNC-Lavalin affair, with Wilson-Raybould subsequently winning her seat as an independent in 2019), and Han Dong's March 22, 2023 departure from the Liberal caucus (over allegations of foreign election interference).

Floor crossing is criticised as undermining democratic accountability (voters elected the MP thinking they would represent a specific party). NDP MP Murray Rankin's Bill C-251 of 2014 would have required MPs who cross the floor to resign and seek re-election in a by-election; the bill did not pass. Some provinces have considered or implemented restrictions on provincial floor crossing. Manitoba's MLA Floor Crossing Act of 2006 requires Manitoba MLAs who change parties (other than to sit as independents) to resign and seek re-election. The federal Reform Act, 2014 made it harder to remove an MP from caucus (requiring formal caucus vote) but did not restrict voluntary floor crossings.