OTTAWA - Marc Garneau is test-firing the engines on his leadership campaign, but he's not ready for liftoff just yet.

The Montreal MP, Canada's first astronaut, says he's in "stage three" of deciding whether to run for the leadership of the federal Liberal party.

Garneau says he's ticked off the first two stages: determining whether there's support for his candidacy and whether he has something unique to offer in the contest.

Now, he's in the process of determining whether he can pull together an experienced team to raise money, sign up supporters and organize an effective campaign.

The once-mighty Liberals, reduced to a third-party rump in the 2011 election, are to choose a new leader in April.

The party is expected to unveil some of the rules for the contest — including the entry fee and spending limit — early next month at a Liberal caucus retreat.

Most potential contenders, including presumptive front-runner Justin Trudeau, are waiting to see the rules before making a final decision.

But Garneau said the rules will have no bearing on his decision, which he intends to make "sometime this fall." Regardless of the spending limit, he said he'll only spend as much money as he can raise.

"I will not go into debt, I can tell you that right now," he told a news conference.

Garneau said he'd prefer an entry fee in the range of $25,000, sufficient to "discourage non-serious candidacies."

In the last full-blown Liberal leadership contest in 2006, the party imposed a $50,000 registration fee and allowed each candidate to spend up to $3.4 million. Most contenders, including winner Stephane Dion, emerged with huge debts, some of which have still not been paid off.

Insiders say party brass are looking at a considerably lower spending limit this time, in the range of $500,000 to $750,000.

But some Liberals maintain the limit should be higher, arguing that the ability to raise money is a big part of the challenge facing the cash-strapped party's next leader.

A higher limit would benefit Trudeau, whose celebrity status has made him the party's best fundraising draw.

Trudeau, the son of party icon and former prime minister Pierre Trudeau, initially insisted he would not run for the leadership. But he succumbed to intense pressure to reconsider after interim leader Bob Rae announced in June that he will not to seek the permanent job.

He and his wife, Sophie Gregoire-Trudeau, are taking the summer to ponder the impact of a leadership bid on their young family. While most Liberals expect him to take the plunge, insiders say Trudeau has made no final decision as yet.

Also on HuffPost:

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  • Surprising Justin Trudeau Facts

    With talk of Trudeau making a bid for the Liberal leadership reaching a fever pitch (again), HuffPost takes a look at some surprising facts about Canada's perpetual PM-in-waiting. (CP)

  • 11. Politics On Mother's Side Too

    Trudeau's maternal grandfather <a href="http://en.wikipedia.org/wiki/James_Sinclair_(politician)" target="_hplink">James Sinclair</a> was a Liberal MP and cabinet minister in Louis St.-Laurent's government in the 1950s. (House of Commons) <em><strong>CORRECTION</strong>: An earlier version of this slide incorrectly said Sinclair was a Progressive Conservative MP.</em>

  • 10. Born In Office

    <a href="http://en.wikipedia.org/wiki/Justin_Trudeau" target="_hplink">Trudeau was only the second child ever to be born while a parent was prime minister</a>. The first was John A. Macdonald's youngest daughter Margaret Mary Macdonald. Trudeau's younger brothers, Alexandre (Sacha) and Michel were the third and fourth. (CP)

  • 9. Educated Enough?

    Trudeau has a Bachelor of Arts degree from McGill and a Bachelor of Education from UBC. He also studied engineering at the Université de Montréal and environmental geography at McGill, but never finished degrees in those fields.

  • 8. Enemies To Friends

    While fathers Brian Mulroney and Pierre Trudeau were rivals, sons Justin and Ben are friends. Mulroney attended Trudeau's wedding to Sophie Grégoire. Grégoire has worked as Quebec correspondent for CTV's eTalk, which is hosted by Mulroney. (CP)

  • 7. Let Them Eat Anything But Cake

    Trudeau didn't have cake at his wedding, with <a href="http://www.macleans.ca/canada/national/article.jsp?content=20050606_106678_106678" target="_hplink">Sophie arguing that people never eat it anyway</a>. (Shutterstock)

  • 6. Born On Christmas

    <a href="http://en.wikipedia.org/wiki/Justin_Trudeau" target="_hplink">Trudeau entered the world on December 25, 1971</a>.

  • 5. Two Tattoos In One

    Trudeau has a large tattoo on his left shoulder. <a href="https://twitter.com/#!/justinpjtrudeau/statuses/179973685136998400" target="_hplink">The planet Earth inside a Haida raven</a>. Trudeau got the globe tattoo when he was 23 and the raven when he turned 40. (Media Ball)

  • 4. Keeping It In The Family

    Trudeau and his wife Sophie have two children, Xavier James (4) and Ella-Grace Margaret (3). Both are partially named after family.<a href="http://www.chatelaine.com/en/article/4970--the-littlest-trudeau" target="_hplink"> Xavier James is named after Trudeau's maternal grandfather James Sinclair</a> (the politician) and <a href="http://en.wikipedia.org/wiki/Sophie_Gr%C3%A9goire" target="_hplink">Ella-Grace Margaret is named after Trudeau's mother Margaret and Grace Elliot, Trudeau's paternal grandmother</a>. Xavier also happens to share a birthday with Pierre Elliott Trudeau. (CP)

  • 3. Politician And Actor

    <a href="http://www.imdb.com/title/tt0846011/" target="_hplink">Trudeau played Talbot Mercer Papineau</a> in the 2007 CBC miniseries "The Great War."

  • 2. .. And Video Game Star

    <a href="http://arts.nationalpost.com/2011/09/06/in-deus-ex-justin-trudeau-is-the-pm-and-canada-has-a-problem-with-illegal-immigrants-from-the-u-s/" target="_hplink">Trudeau is prime minister in the dystopian future portrayed in the video game Deus Ex: Human Revolution</a>. (CP)

  • 1. Childhood Sweathearts

    Sophie used to visit the Trudeau family home when she was a child. She was a classmate and friend of Trudeau's youngest brother Michel, who died tragically in a B.C. avalanche in 1998. Justin and Sophie made contact again at a fundraiser in 2003 and soon after began dating. <a href="http://www.macleans.ca/canada/national/article.jsp?content=20050606_106678_106678" target="_hplink">Trudeau was so smitten</a> that he declared they would spend the rest of their lives together on the very first date. (CP)