Explained | What happens now that Trudeau is resigning as Canada's PM?

Ottawa: Canadian Prime Minister Justin Trudeau on Monday said he would step down in the coming months after nine years in power, bowing to legislators alarmed by his Liberal Party's miserable pre-election polling numbers.

Trudeau said he would stay on both as prime minister and Liberal head until the party chooses a new leader to take it into the next election, which must be held by late October this year. Here is what might happen next:

Will Trudeau leave office immediately?

No. Trudeau will stay on both as prime minister and head of the ruling Liberal Party for now. Unlike the process in other countries like Australia, where party leaders are elected by legislators and can be removed overnight, in Canada they are chosen by special leadership conventions that can take months to organize.

Will an election be held in the near future?

No. Trudeau announced that parliament - which had been due to resume work on January 27 - would instead be prorogued, or suspended, until March 24.

This means opposition parties who had originally planned to unveil non-confidence motions to bring his minority government down as soon as they could after January 27 will now have to wait until some time in May since the government controls the agenda for most of each session. If all the opposition parties vote together on the motion, the Liberals will be defeated and a new election called.

As a result, a new election is unlikely to be held before May at the earliest.

When parliament resumes, the government has to formally unveil its plans for the new session in the so-called Speech from the Throne. The Liberals are not obliged to make this subject to a vote of no confidence.

Parliament is scheduled to start its summer break no later than June 20 and if the Liberals are still in power by then, an election would be held as scheduled at the end of October.

How else could the liberals be removed from power?

Under the original parliamentary calendar, the House of Commons elected chamber had been due to vote on spending measures in late March. This would trigger a confidence vote.

It is unclear whether that vote would still be scheduled for late March and if it were, whether the opposition parties would vote to bring down the Liberals, whether they are led by Trudeau or a new party head. The Conservatives, who are favored to win the next election, and the left-leaning, small New Democratic Party have both made clear they want to defeat Trudeau on a formal motion of no-confidence that they themselves have presented.

The Liberals could also be brought down over their annual budget, which would most likely be unveiled in April. The initial vote on the legislation implementing the budget would be a matter of confidence but the government has some flexibility as to when that would take place.

How long does the party have to chose a new leader?

The nightmare Liberal scenario is that the party takes so long to choose a new leader that it has to fight the next election with Trudeau still in charge. It is likely therefore to announce a shortened contest designed to ensure that Trudeau's replacement is in office as soon as possible.

When Trudeau won the Liberal leadership in April 2013, the contest lasted exactly five months. In 2006, it lasted almost eight months.

Trudeau said he had asked the party to start the process of choosing a new leader. Liberal president Sachit Mehra said he would call a meeting of the party's national board this week to begin the process. He gave no further details.

Would a news leader help the liberals avoid defeat?

Polls strongly indicate that the Liberals will lose the election, no matter who the leader is. But the scale of the defeat could be tempered if Trudeau is not in charge.

Who might run to replace Trudeau as liberal leader?

The prospect of an election mauling might deter some candidates, especially if the party is crushed and ends up a shadow of its current self. Those who could run include Innovation Minister Francois-Philippe Champagne, Transport Minister Anita Anand, Foreign Minister Melanie Joly as well as former finance minister Chrystia Freeland and Mark Carney, former governor of the Bank of Canada and the Bank of England. Tradition dictates that Carney, currently Chair of Brookfield Asset Management, would need to secure a seat in parliament in order to take office if he won the party leadership.

Is there any other way Trudeau can be forced out?

Ultimate constitutional power in Canada lies with Governor General Mary Simon, who is the personal representative of Britain's King Charles, the head of state. She can in theory remove Trudeau, but there is virtually no chance of that happening.

"The governor general won't dismiss a prime minister who still holds the confidence of the Commons," said Philippe Lagasse, a professor and constitutional expert at Ottawa's Carleton University.