Two prominent Liberals, one a newly minted MP and the other a former cabinet minister, entered the race for the party's leadership as it officially began on Friday.

Michael Ignatieff, an academic and newcomer to the House of Commons, announced his candidacy in his Toronto riding of Etobicoke-Lakeshore.

Stéphane Dion, who has been a member of Parliament in the Montreal-area riding of Saint-Laurent-Cartierville since 1996, also joined the contest.

Stéphane Dion announces his bid to run for the Liberal leadership, Montreal, Friday.

The two entered the race shortly after the party issued the official call for its leadership and convention, to be held in Montreal Nov. 28-Dec. 3.

Dion, 50, touted his record on the environment as he announced his candidacy at Montreal's Palais des Congrès, the site where he led international greenhouse-gas reduction negotiations in December and where the new Liberal leader will be chosen.

"Underlying our Liberal philosophy is a conciliation of two great human ideals, that is individual freedom and equal opportunity. I propose that we add another – a healthy environment," he said.

Michael Ignatieff announces that he is joining the Liberal leadership race, Toronto, Friday

Dion is currently the Liberal foreign affairs critic, and served as environment minister in Paul Martin's government.

He is also known as the architect of the federal Clarity Act, which sets out rules regarding any referendum on Quebec sovereignty.

"I'm proud of both my Quebec identity and my Canadian identity," Dion told reporters on Friday. "Identities are to be added, not subtracted."

Ignatieff stresses party renewal

Ignatieff, a 58-year-old author and former Harvard professor, talked about helping the party regain the support it lost when the Conservatives won a minority government in January.

"I am fighting to revive faith, not just in the Liberal party, but in politics itself," he said. "I'm a devoted Liberal, I've been one all my life. That's why I'm in the fight to renew the party I love.

"Renewal of the party mostly means that we must conquer anew the sense of belonging of francophones in Quebec," he added.

"Social values and the progressive values of Quebecers one and all are not blue; they are red, and they will always remain red."