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.

News from © The Canadian Press, 2012