After a slow summer on the leadership front, a race for the federal Liberal crown could soon start picking up speed.

MPs and senators are gathering in Montebello, Que., to plan the fall sitting of Parliament, but the party is also expected to announce the rules for the contest to become the next head of the federal Liberal Party.

While two candidates have already declared their leadership ambitions and a handful of others say they're considering running, no current or former MPs have announced they want to lead the party.

The party plans to outline the rules for the race, including spending limits, at the end of this week's caucus retreat. That could prompt some potential candidates to say whether or not they will run.

Others, however, may be waiting to see whether Quebec MP Justin Trudeau, son of former prime minister Pierre Trudeau, will try to follow in his father's footsteps. Many Liberals believe he'd be too tough a challenger to beat.

Candidates mum on decision

Several possible candidates talked about what they're considering as they make the decision whether to run, but no one would tip their hand in the first day and a half of Liberal caucus meetings.

Montreal MP Marc Garneau, a former astronaut, says as an engineer he's doing his homework: making calls, confirming support and trying to decide whether he has a national network of volunteers and donors.

"I'm encouraged. I think people — they've heard me speak on a lot of issues in a lot of different policy areas, and I think they view me as a person of substance, and I tell them that I want to make some very bold changes. Bold changes to the way that Canada is being run at the moment," Garneau said.

"If I reach the point where I say, yeah, I got it, then I'll be very public about it."

New Brunswick MP Dominic LeBlanc, whose father Roméo was an MP and governor general, says he's weighing family issues with what he expects would be a 10-year commitment to the party. LeBlanc ran for the leadership four years ago.

"I did in 2008. If I did in 2008, I don't know why I wouldn't want to four years later, although circumstances have changed both in terms of the party itself and my own personal circumstances," he said.

LeBlanc's wife is a judge, who can't attend political events with him. And her career is as important as his, he pointed out.

Asked whether he'd considering running to replace outgoing Quebec Liberal Leader Jean Charest, Montreal MP Dénis Coderre told reporters he wasn't at the caucus meeting to shop around. He has also said he's considering a run for the federal leadership.

Party out of debt

The rules are due to be settled Wednesday night and announced Thursday at the caucus's closing press conference.

Interim Liberal Leader Bob Rae wouldn't talk about spending limits or other rules for the leadership contest Tuesday as MPs and senators started arriving for the annual planning session.

LeBlanc says he's been arguing for "reasonable" spending limits and "severe" borrowing limits.

"We shouldn't pretend that we can raise and spend millions of dollars that I think, a) would be unwise and, b) would leave people in a vulnerable position in terms of debtload," he said. "If you can't raise it as you're going, why do you think it would be better to raise it after you've lost?"

He's also calling for "a reasonably high" non-refundable deposit to weed out less serious candidates.

"I don't think if somebody wants to practice something that they learned at the Toastmaster's Club about speeches, a national leadership convention is the best place to have a practice run," LeBlanc said.

Even though the Liberals dropped from 77 to 35 seats in the House of Commons after the 2011 election, Rae says the party is in a good financial position as it moves toward the leadership race.

"We don't have any debt, we have money in the bank, we have more money coming in every month than we're spending. We have a very strong situation as far as the organization of the party is concerned, we have new members coming in, more supporters coming in ... so I think it's going to be a very active fall and winter and spring for the Liberal Party of Canada," he said.

Rae says he will suggest to caucus that any MPs running for the position be allowed to keep their critic portfolios. The NDP did the opposite in its leadership race, having high-profile critics on files like finance and foreign affairs step aside for, in some cases, less experienced faces. Many candidates said it relieved a burden when they were already juggling constituency and leadership contest duties.

"I don't think they should be required to stay away from the House of Commons," Rae said.

"I think they should be encouraged to continue to participate in the life of the caucus, continue to be effective spokespeople for the Liberal Party of Canada. We need all hands on deck as we go forward and I'm going to continue to make that recommendation to the caucus."

Only two declared candidates

Longtime Liberal Deborah Coyne, mother of Pierre Trudeau's only daughter, is the only Liberal who threw her hat into the race this summer.

Coyne said she believes she has a vision and a program that will resonate with Canadians.

Shane Geschiere, a Manitoba resident, had declared his intention to run for the leadership earlier in the year.

Of course, all eyes will be on Trudeau who has never denied having leadership ambitions but said any decision would be made in consultation with his family.

Other Liberals who are said to be mulling over the decision to take the plunge include Ottawa MP David McGuinty and former MPs Gerard Kennedy, Mark Holland and Martha Hall Findlay, as well as one-time candidates David Bertschi and Taleeb Noormohamed and Toronto lawyer George Takach.

Rae surprised Liberals when he opted out of the race in June saying the best way he could serve the Liberals was "by not running for the permanent leadership."

With files from Susana Mas