Prime Minister Justin Trudeau will face down his own caucus members in a hotly anticipated meeting this morning, as several of them plan to try to convince him to step aside.

Rumours have circulated for weeks about an undisclosed number of Liberal MPs who have signed on to the effort to oust the prime minister in the hopes of improving the party鈥檚 chances in the next election.

That promises to make the regular weekly caucus meeting on Parliament Hill extra tense, as Trudeau has showed no signs of stepping down from the top job.

Trudeau鈥檚 personal poll numbers plummeted more than a year ago, and successive byelection losses have compounded concerns about his leadership.

The MPs have no formal mechanism to depose Trudeau as leader, which means the decision is ultimately up to him.

It鈥檚 not yet clear how many MPs will confront Trudeau, or exactly what message they plan to deliver behind closed doors.

Here鈥檚 what you need to know ahead of this meeting.

Why do some MPs want Trudeau to step down?

Polls have shown that Trudeau鈥檚 popularity has waned among Canadians for more than a year and some MPs believe he won鈥檛 be able to lead the Liberal party to victory again in the next election.

Where Trudeau鈥檚 popularity once helped lift his party up, the dissatisfaction Canadians now have about his leadership is dragging the party down.

It鈥檚 an increasingly urgent concern for Liberals as a fall election became a much more likely possibility. In September the NDP ended their supply and confidence agreement with the Liberals and will now decide on support for the government on a case-by-case basis. The Bloc Qu茅b茅cois has also issued the Liberals an end-of-October ultimatum to support a pension bill before the Bloc pulls its support.

While some MPs have previously said Trudeau should go, a movement to oust him began to gain steam in the first two weeks of October while Trudeau was overseas at international summits in France and Laos. He cancelled plans to attend the Commonwealth summit in Samoa this week as domestic issues bubble at home.

Liberal MP Sean Casey was the first to publicly confirm that he signed a letter calling for Trudeau鈥檚 resignation but hasn鈥檛 said how many other MPs have joined him.

On Monday, Casey said Canadians are no longer listening to Trudeau and that he has become a distraction.

鈥淭here鈥檚 been baggage accumulated. People have tuned him out,鈥� Casey told reporters.

Most cabinet ministers have spoken out in Trudeau鈥檚 defence but some have acknowledged Wednesday鈥檚 meeting could be tense.

It鈥檚 highly unlikely that Trudeau would step down as a result of Wednesday鈥檚 meeting, said Scott Reid, who worked as the director of communications for former prime minister Paul Martin.

However, he said the situation will nonetheless hang over him as the next election looms.

鈥淓ven someone with the record of success and the tremendous reserves of confidence that Justin Trudeau enjoys, I think that鈥檚 going to weigh on you,鈥� Reid said.

鈥淵ou鈥檙e still left with the heavy weight of dissent toward your leadership, and you鈥檝e got to carry that around.鈥�

What are Trudeau鈥檚 options?

If he decides to capitulate to the MPs鈥� demands, Trudeau could announce he will step down immediately, or he could announce he won鈥檛 run for re-election.

So far he has been steadfast in his assertion that he is going nowhere, including Tuesday morning when he said 鈥渘o鈥� when asked if his leadership was in danger.

If he changes his mind, he could stay on until a new leader is chosen, or resign immediately. If he does the latter, an interim leader would fill in to head the party while a leadership race takes place.

If he resigns while his party is still in power, it could leave the Liberals vulnerable to an early election. Without a permanent Liberal leader, the NDP might see a better chance for their own fortunes and vote against the government in the next confidence motion.

Trudeau could prevent that by proroguing Parliament 鈥� which would essentially terminate the current session and hit the reset button, which could allow time for a Liberal leadership race if he did step down.

Deputy Prime Minister Chrystia Freeland said Tuesday the government has no intention of proroguing.

Can MPs force him to step down, or at least force a leadership review?

There is no mechanism that would allow the Liberal caucus to force Trudeau鈥檚 resignation because the Liberal caucus did not opt to endorse a bill that would give Liberal MPs the ability to force a leadership review from within the caucus.

The Conservatives were the only party to opt in to the Reform Act after the last election, and it was that which led to the secret ballot vote that ousted their former leader, Erin O鈥橳oole, in early 2022.

Neither is there one to force a leadership review from the party as a whole 鈥� in fact, the party鈥檚 constitution doesn鈥檛 have a mechanism for such a review, unless the party has been defeated in a general election.

What would a Liberal leadership race look like?

If Trudeau does resign, the national president of the party must call a board meeting within 27 days to discuss the leadership race. The board must create two committees, one to manage the expenses for the leadership contest and one to plan, organize and carry out the vote.

Potential nominees must deliver their nomination at least 90 days before the vote.

If a leadership race happens it will likely be on the short side, said Reid.

鈥淭ypically, when you鈥檙e in government, particularly if you鈥檙e in a precarious minority Parliament, you would think that the race would likely be shorter because you don鈥檛 want to go long without a prime minister who鈥檚 also the leader of his party,鈥� he said.

However, he said it鈥檚 quite uncommon for a ruling party with a minority to hold a leadership race.

Who would run to replace Trudeau?

There is a growing number of cabinet ministers on a list of possible successors, some just through the rumour mill, while some have begun quietly organizing for a future run whenever it may be.

Those lists of potential candidates include Freeland, Industry Minister Fran莽ois-Philippe Champagne, Foreign Affairs Minister M茅lanie Joly, Housing Minister Sean Fraser, Public Safety Minister Dominic LeBlanc and Treasury Board President Anita Anand.

Former Bank of Canada governor Mark Carney and former B.C. Premier Christy Clark have both hinted at a possible run as well.

Carney was tapped in September to lead the Liberals鈥� economic task force ahead of the next election and has been flirting with a run for politics for years.

On a recent episode of Uncommons, a podcast by Liberal MP Nate Erskine-Smith, Carney was asked whether his own name could be on a ballot at some point.

鈥淚鈥檓 taking steps that support that,鈥� said Carney, adding, 鈥渢he opportunity may present itself.鈥�

In a statement Monday Clark said she has 鈥渘ever closed the door on the possibility of one day returning to politics.鈥�

鈥淭he position of Liberal leader is not going to be available any time soon,鈥� she said.

鈥淚f that were to change, I would want to be part of the conversation on the future direction of the Liberal party and of the country.鈥�