CTV News has learned that on Friday, two Liberal MPs will formally announce their quest to seek their party's leadership.

The two are Stephane Dion and Michael Ignatieff.

Dion, 51, has been in elected politics since 1996. He left his life as an academic to join the Liberal government of then-prime minister Jean Chretien, who appointed him minister of intergovernmental affairs.

In that portfolio, Dion became known as an aggressive defender of federalism.

When Paul Martin became prime minister in December 2003, he dropped Dion from cabinet, but then brought him back in after the 2004 federal election. Dion then served as minister of the environment.

Dion is currently serving as the Liberal foreign affairs critic.

The policies Dion plans to tout are sustainable development and creating a "super-educated" workforce to compete in the global economy.

Ignatieff, 58, is a newcomer to elected politics. He successfully ran in the Toronto-area riding of Etobicoke-Lakeshore, in which some of his most aggressive opponents were disaffected Liberals opposed to someone they saw as a "parachute candidate."

For most of his life, Ignatieff has been a journalist, author and academic. His last posting was at Harvard, where he headed the Carr Centre for Human Rights.

He is the associate Liberal critic for human resources and skills development in this Parliament.

Ignatieff gave a speech at the University of Ottawa last Thursday. In it, he laid out his thoughts on issues like Quebec, international affairs and decentralization of the Canadian federation.

Two other candidates have said they are running: Toronto lawyer Martha Hall Findlay and Toronto MP and former cabinet minister John Godfrey.

Numerous other candidates are considering bids, but have yet to formally declare themselves.

The Liberal Party set April 7 as the official kickoff day of the campaign to replace Paul Martin, who said on the night of the Jan. 23 federal election he would step down.

"On the weekend, in Edmonton, an interesting event: The Alberta Liberal Party is going to have a round table with many of the people who want be leaders of the party," said CTV's Craig Oliver. Reported participants include Ignatieff, Dion, Belinda Stronach and many others, he said.

The party holds its leadership convention on Dec. 2-3 in Montreal.