Former astronaut and Montreal MP Marc Garneau launched his Liberal leadership bid Wednesday, joining an already crowded field of those hoping to win the party's top job.

Garneau made the announcement Wednesday morning in his riding of Westmount-Ville-Marie. Alternating between French and English, a fiery Garneau said it's time for the Liberal party to set aside issues that divide and focus on those that unite.

"As leader, I will focus on the issues that matter to Quebecers and indeed to all Canadians. I will do this by making the economy my number one priority because I have to say it, how we propose as Liberals to deal with the economy will be crucial not only to our fortunes but to our country," Garneau said.

The former Canadian Space Agency chief said Canada has become "angry, divisive and intolerant" under the leadership of Prime Minister Stephen Harper and it's "time for change."

"I'm talking serious change to my party and my country. My goal is to restore integrity and principled leadership to Canadian politics," Garneau said.

Earlier in the week, B.C. MP Joyce Murray also announced her intention to compete for the leadership position. As part of her bid, she said she would, as leader, enter talks with the New Democrats and Greens before considering fielding a single candidate in tightly-contested ridings during the next federal election.

Garneau said he wasn't open to such a measure, saying he would field a Liberal candidate in every riding in Canada if elected leader. However, he conceded there is a sense among many Liberals that the party is being squeezed on the right by the Conservatives and on the left by the New Democrats.

"To those of you who think we might get crushed, let me say this: never! Canada needs a Liberal party committed to everyday Canadians," Garneau said emphatically.

Hours later on CTV’s Power Play, Garneau continued his attack on the Conservative-led government, saying Harper has “totally neglected” Canada’s knowledge-based economy.

“We are a country that, if you compare us to our competitors, should be much better,” he said, adding that promoting that workforce will be his “relentless focus.”

Garneau said he will introduce savings for Canadians starting with military procurements, and singled out the replacement of Canada’s aging fleet of CF-18 fighter jets.

“We will have a replacement for the CF-18 but it will be one that will save us billions of dollars because this government has totally made a fiasco of that.”

While candidates continue to enter the leadership fray, Justin Trudeau is widely considered the frontrunner in the field that also includes Toronto MP Martha Hall Findlay, Toronto lawyer Deborah Coyne, Ottawa lawyer David Bertschi, Vancouver prosecutor Alex Burton and former president of the party's B.C. wing, David Merner.

In the coming days, at least two other Ontario candidates are expected to announce their intention to run.

The third-place Liberals will choose a successor to interim leader Bob Rae on April 14, 2013 at a leadership convention in Ottawa.

Garneau, 63, was first elected to the House of Commons in 2008 after a high-flying career as an astronaut. He became the first Canadian to fly in space in October 1984, when he participated as a payload specialist on Shuttle Mission 41 -- paving the way for a number of Canadian astronauts who have followed in his footsteps.

He went on to fly on two additional NASA space missions, then became executive vice-president of the Canadian Space Agency in 2001, and later president of the organization. He left that position in 2005 to pursue a career in politics.

Garneau said he has no qualms about “flogging” his platinum-plated resume.

“There will be no modesty here,” he said.

A companion of the Order of Canada, Garneau has two high schools named after him in Toronto and Trenton, Ont. And perhaps more impressive for science-fiction fans, he also had a spaceship named after him in the popular Star Trek series -- the USS Garneau, according to his official biography.

Garneau has been married to his wife Pamela Soame for 16 years, and the couple has two children together. He also has two children from a previous marriage.