Former NDP premier of Ontario Bob Rae had made it official: He wants to become the next leader of the federal Liberal Party.

The 57-year-old did so in Toronto on Monday by saying he wanted to talk about the future of the country.

"I am running as a Liberal for the leadership of the Liberal Party because I believe that Canada needs a party that embraces change, that is open ... to all Canadians, that understands that politics is about serving people, it is not about theories or ideologies," he said.

"The Liberal Party of Canada understands that politics works best when we are committed to the middle way to solving problems, to seizing opportunities ...," Rae said.

"I have been attracted to the Liberal Party over the years because it is optimistic, because it builds on hope and not on fear," he said.

In acknowledging the support of two high-profile provincial Liberal politicians from Ontario -- Greg Sorbara and Health Minister George Smitherman -- Rae said he'd been made to feel welcome. "It is an open party, and I can assure you that under my leadership, it will become even more open to all Canadians as we strive to move forward," he said.

Rae joined the Liberals a few weeks ago, a move many believed would lead to him throwing his hat into the leadership race.

The Rhodes scholar will have a few obstacles to overcome. The first being that he'll have to convince the Liberals of his commitment to the party.

The second liability he faces is dispelling doubts over the five turbulent years he spent as Ontario's premier before being kicked out by irate voters in 1995.

However, Rae pointed out in an interview with CTV's Canada AM that he became premier in 1990, just as Ontario was plunged into the worst economic recession since the 1930s.

"My barber has an expression. He says anybody can sail in good weather. I had to sail in the toughest seas we had -- the toughest weather we had. That's just the reality."

He also admits that he may have made some mistakes.

"Did I make mistakes as a 40-year-old premier? Yes, of course I did. But here I am. I've learned a lot from my experiences."

In his 10-year hiatus from politics, Rae has headed inquiries into the Air India tragedy and post-secondary education in Ontario. He has also advised governments in Sri Lanka and Iraq.

Earlier Monday, Toronto MP Carolyn Bennett joined the race. Nova Scotia MP Scott Brison announced Sunday, and Toronto MP Joe Volpe announced Friday.

Other candidates include Maurizio Bevilacqua, Michael Ignatieff, Stephane Dion and Martha Hall Findlay.

Gerard Kennedy, until recently Ontario's minister of education, is expected to join the race, as is Toronto MP Ken Dryden.

The Liberals will select their new leader at a convention in Montreal set for early December.