An Act to amend the Parliament of Canada Act

Bill C-278 would change what happens when a Member of Parliament switches political allegiance after being elected. Under the new rule, if an MP was elected as a candidate for one registered party (or as an independent) and later joins a different registered party, that MP's seat is automatically considered vacated and they immediately lose their status as a member of the House of Commons.

The process would work like this: the leader of the party the MP has newly joined must promptly notify the Speaker of the House of Commons in writing about the change. Once the Speaker receives that notice, they must formally order the Chief Electoral Officer to issue the paperwork for a by-election to fill the now-empty seat. If there is no sitting Speaker, the Speaker is out of the country, or it is the Speaker's own seat that has become vacant, the party leader instead sends that order directly to the Chief Electoral Officer.

In effect, this bill would end the practice of MPs "crossing the floor" to sit under a different party's banner while keeping the seat they were elected to. Instead, any such switch would trigger a fresh by-election, giving voters in that riding a chance to elect a new representative under the changed political circumstances. This bill does not affect MPs who leave their party to sit as independents, only those who join another registered party.

This bill amends the Parliament of Canada Act to automatically vacate a Member of Parliament's seat, triggering a by-election, if the MP joins a registered party different from the one that endorsed them in the last election (or joins any party after running as an independent).

• Trigger for vacancy — a seat is deemed vacated automatically once an MP elected as an independent, or endorsed by one registered party, becomes a member of another registered party; no separate decision or vote is required.
• Notice obligation — the leader of the party the MP has newly joined must, "without delay," notify the Speaker of the House of Commons in writing that the person is now a member of that party.
• Speaker's role — on receiving that notice, the Speaker must address a warrant to the Chief Electoral Officer to issue a writ calling a by-election for the vacant seat; this step is procedural, not discretionary.
• Alternate procedure — if there is no Speaker, the Speaker is absent from Canada, or the vacating member is the Speaker, the party leader instead signs and sends the warrant directly to the Chief Electoral Officer.
• Scope not defined — the bill does not specify how "becomes a member of a registered party" is determined or verified, or address disputes over whether or when a change of affiliation occurred.
• Oversight — the bill sets out no appeal mechanism, review process, or sunset clause for this new vacancy rule.