Many are asking, will Carney automatically become prime minister just because he's the new Liberal Party leader?
Let me explain how this works. Right now, Carney is set to become prime minister, but Trudeau is still officially prime minister until the handover occurs. First, Trudeau must tender his resignation to the Governor General, who would then be in the position to ask his successor—Carney—to form a government as PM.
In Canada, a prime minister doesn't need to be an Member of Parliament to serve as leader of the country. While it doesn't happen often, this is allowed under our system of government.
Because Carney will not be allowed to sit on the floor of the House of Commons without being elected MP, it is unlikely he would wait until the fixed election date. An unelected PM, who has not won a seat in Parliament, cannot participate in votes or debates on the floor of the House of Commons.
@BC_FreedomFighters