Switching horses: Alleslev isn't the first MP to cross the floor
It's rare, but it happens. And there's nothing in the rule book to stop it.
Leona Alleslev is just the latest MP to take part in the time-honoured Canadian political tradition of switching team jerseys between elections.
Elected in 2015 as a rookie Liberal MP, Alleslev stunned a lot of people today when she stood in the House of Commons and announced she was joining the Conservative bench.
After a highly critical speech condemning Liberal leadership and party policy, she walked across to the opposition benches and assumed her new seat behind Conservative Leader Andrew Scheer.
Over the years, many MPs have been either kicked out of their party's caucuses or have left voluntarily, citing political principles, party position or concerns about leadership.
The act of actually switching parties — known as "crossing the floor" — is a lot more dramatic and a lot less common, although there have been three high-profile instances of floor-crossing in recent years:
February 9, 2015, Eve Adams joins the Liberals
Heads turned in February 2015 when high-profile MP Eve Adams left the governing Conservatives to join the Liberal Party, citing "mean-spirited leadership" as her motive. She ultimately lost the Liberal nomination to run in the 2015 election to Marco Mendocino.
May 17, 2005: Belinda Stronach joins the Liberals
Jaws dropped when business magnate Belinda Stronach left the Conservatives, after vying for the party's leadership, to join Paul Martin's Liberal cabinet in 2005. Her defection was engineered to keep Martin's minority government in power as it faced two key budget votes.
Feb. 6, 2006: David Emerson joins Conservatives
Another stunner occurred on Feb. 6, 2006, when David Emerson joined the Stephen Harper cabinet — just two weeks after he was elected as a Liberal in the Vancouver-Kingsway riding. Some voters and riding association officials were angry that he crossed the floor so soon after the election.
Today's move by Alleslev came just after the seating arrangement in the House of Commons had been changed to reflect a few other MPs changing their political profiles.
Maxime Bernier, who left the Conservatives last month to create his new People's Party of Canada, assumed his new seat at the rear of the chamber today. Erin Weir, who was banished from the NDP, chose to sit as a member of the Co-operative Commonwealth Federation, a party that has been defunct since 1961.
Also today, five Bloc Québécois MPs who quit the party earlier this year announced they are returning to their old caucus.
Seven of the party's 10 MPs had quit in February over former leader Martine Ouellet's style; they started their own party, Québec Debout. Two others rejoined the Bloc after Ouellet stepped down in June after losing a confidence vote.
But while there may be political consequences for changing party affiliation, there's nothing else to prevent it. According to the Library of Parliament, the only federal legislation that specifically addresses changes in caucus membership is the Parliament of Canada Act, which says that caucuses can choose to require that the expulsion or readmission of caucus members be put to a vote.
Bills have been introduced in Parliament in past that would force a floor-crossing MP to seek re-election under the new party banner through a by-election; to date, none of them has been adopted.
NDP bans floor-crossing
The NDP has a policy which requires a defecting MP to either sit as an independent until the general election or run in a by-election before joining its party's bench.
Between 1867 and 2015, 274 MPs either switched their party affiliations or dropped them to sit as independents.
Some countries have adopted measures to discourage parliamentarians from changing party affiliation, while others have prohibited any limits on parliamentarians' freedom of action, according to the Library of Parliament.
About 40 nations have legal or constitutional provisions that penalize parliamentarians who change parties, and in most cases the defectors are required to give up their seats.
New Zealand passed legislation to discourage floor crossing in 2001, but when the law expired in 2005, a parliamentary committee rejected it on the grounds that it did not improve public confidence in Parliament as an institution.
France, Germany, Greece and Italy have laws that bar any restrictions on parliamentarians' freedom of action.