The Liberals are about to choose the next prime minister. What happens next?

Prime Minister Justin Trudeau leaves the stage after speaking at the National Forum on Combatting Antisemitism, Thursday, March 6, 2025 in Ottawa. THE CANADIAN PRESS/Adrian Wyld

OTTAWA — The Liberals will choose a new leader Sunday, marking the end of Justin Trudeau’s decade as prime minister.

He will step down officially in the days to come. On Tuesday, Trudeau said he will have a conversation with the incoming leader to determine exactly when that will happen.

“It should happen reasonably quickly, but there’s a lot of things to do in a transition like this, particularly in this complicated time in the world,” Trudeau said.

Here’s a look at what comes next.

The handover

First, Trudeau needs to formally resign as prime minister. He’ll meet with Gov. Gen. Mary Simon and, on his advice, Simon will invite the new Liberal leader to form a government.

That could happen right away, said David Zussman, an adjunct professor in the school of public administration at the University of Victoria who has written a book about political transitions. Or it could take days, or weeks.

“Justin Trudeau could, in fact, be sitting in his seat in the House of Commons when the House comes back at the end of March,” he said.

But that seems unlikely.

On Thursday, Trudeau insisted he does not plan to stay on in a caretaker role during the next election.

The new leader is likely to want to get started soon, Zussman said.

Forming a government

The new leader needs to name a cabinet and set a date to swear them in.

Trudeau’s cabinet has 37 members. Some ministers could stay on, or there could be new faces around the table from the Liberal caucus.

Michael Wernick, the former clerk of the privy council, said the new leader has “what the hockey coaches call a short bench” because so many Liberal MPs have decided not to run in the next election.

He suggested a smaller cabinet is likely, with some ministers carrying more than one portfolio.

Zussman said keeping some of the same ministers makes things simple for the public service.

New ministers need to be vetted and set up with things like security and secure phones, drivers and cars.

And everyone has to get up to speed on their files — quickly — because an election is coming in the next six months.

Naming a team

Another team needs to be named quickly: the Prime Minister’s Office staff and key advisers.

New people coming into top staff jobs need security clearances and briefings to get up to speed.

And at least part of the new leader’s inner circle will have to have eyes on the next election, which the leader could call at any point once the cabinet is named.

The Trump effect

Cabinet ministers like Finance Minister Dominic LeBlanc, Foreign Affairs Minister Mélanie Joly, Industry Minister Francois-Philippe Champagne and Public Safety Minister David McGuinty have been leading Canada’s push to convince U.S. President Donald Trump that tariffs are a terrible idea.

The new leader has to decide whether it’s prudent to keep some of these key players in their roles and maintain the contacts they’ve made with counterparts across the border, or whether it’s better to show they’re not — as the Conservatives have charged — “just like Justin.”

Trump’s ever-changing trade policy and foreign policy make this “the most unique set of circumstances I’ve ever observed,” Zussman said.

That will affect the next leader’s cabinet choices and the timing of the next election.

Could Parliament come back?

When Trudeau announced his plans to resign in January, he prorogued Parliament until March 24.

The fall sitting of the House of Commons that ended in December was dominated by a Conservative filibuster that prevented almost all House business from getting done.

The Opposition launched a number of attempts to oust the minority Liberals with non-confidence motions, and the government pushed through only a few pieces of legislation with the help of the NDP.

Returning to the House of Commons to deliver a throne speech and deal with issues of supply would mean the new Liberal government would face confidence votes right away.

The new leader inherits a minority government with no supply-and-confidence deal and an opposition that’s eager to boot the Liberals out.

The Conservatives want the Liberals to reopen Parliament to debate the response to Trump’s tariffs. But the Tories are not promising to hold off on an election if that happens.

When he was asked on Feb. 5 if forcing an election now would be a responsible choice, Conservative Leader Pierre Poilievre said it’s “the only responsible course of action.”

The New Democrats, however, have said they are willing to work with the Liberals in a limited way. NDP Leader Jagmeet Singh said he wants legislation passed to support Canadian workers affected by tariffs and “an election is secondary to that.”

The NDP and Liberals together hold enough seats to pass legislation and defeat motions of non-confidence, but the NDP would want to see specific measures.

Wernick said the new prime minister could work out a deal with other parties to get some things done in a short sitting before heading into an election, but “that requires a level of maturity” beyond what we’ve seen in recent months.

“We can go very quickly into an election right after the swearing-in of a new cabinet,” Zussman said. “That may be a strategic advantage (for the new leader).”

Going to the polls

An election call could come before March 24.

That means all parties need to nominate candidates in 343 ridings. The Liberals, at last count, had about 160 people nominated.

The campaign will last between 37 and 51 days, with the vote landing on a Monday.

“The parties will be enormously distracted during an election campaign,” Zussman said.

“However, it seems to me that we’re going to be negotiating non-stop for as long as Trump is in power. He keeps changing the rules every day, so I don’t know when a good time is.”

It’s important to note that Canada will still have a government that can respond to tariffs and talk to the Trump administration during an election. The cabinet stays in place in caretaker mode, though it’s unable to pass new laws.

“I think a lot of Canadians think that somehow when Parliament is prorogued, we have no government, or when we have an election we have no government,” Wernick said. “There’s no break in Canadian government.”

A brief history lesson

The last time we had a handover of prime ministers within the same party was in 2003, when Paul Martin won the Liberal leadership race.

Martin had resigned as Jean Chrétien’s finance minister in 2002 after a series of disagreements between the two.

Chrétien announced his plans to resign in 2003 and the Liberals chose Martin as their new leader in November that year. Chrétien prorogued Parliament until Jan. 12, 2004 to allow for a transition.

On Dec. 12, 2003, Martin was officially appointed prime minister and sworn into office, along with his cabinet.

The next federal election was held in June 2004 and Martin’s Liberals won a minority government.

Wernick said the transition between former Conservative prime minister Stephen Harper and Trudeau took 16 calendar days.

Canadian transitions are relatively brisk, he said, especially compared to other countries.

In the U.S., elections happen in early November and the inauguration is in late January. Germany, whose government was defeated in December, will have a new government in place in late April.

This report by The Canadian Press was first published March 8, 2025.

Sarah Ritchie, The Canadian Press