Former interim Liberal leader Bob Rae says he鈥檚 leaving federal politics with confidence that his successor, Justin Trudeau, will eventually lead the country.

鈥淗e鈥檚 taking stage as he should do and he鈥檚 going to be the leader for a long time to come and he鈥檚 going to be the next prime minister of Canada,鈥� Rae told CTV鈥檚 Canada AM Thursday, a day after resigning as an MP for Toronto.

The veteran politician said he will always be a phone call away should Trudeau seek out his advice, but believes the new Liberal leader will carve out his own path and learn along the way.

Rae鈥檚 departure has already ignited speculation about who will run for his seat in the Toronto Centre riding.

The Globe and Mail reported Thursday that former Canada AM co-host Seamus O鈥橰egan is rumoured to be a possible candidate.

O鈥橰egan told Canada AM that the newspaper 鈥渢hrew a fast one by me.鈥�

Asked if there is any chance he鈥檚 considering a run for the Liberals, O鈥橰egan took a long pause and only said: 鈥淭his鈥ust floored me. It鈥檚 an auspicious riding.鈥�

He also noted that he and Trudeau are friends.

Rae, 64, acknowledged Thursday that it was a 鈥渧ery hard time鈥� for him to leave, given the tumultuous spring session in the House of Commons and recent polls suggesting the Liberal Party under Trudeau could make a comeback in the next election.

But he said 鈥渋t became very clear鈥� that he would not be able to stay on as an MP and focus on his work as a lawyer and mediator on First Nations issues.

Rae said the decision was an emotional one and he鈥檚 鈥渧ery gratified鈥� by the response from all those who praised his legacy and wished him well.

Rae was the NDP premier of Ontario from 1990 to 1995, and later joined the Liberal Party.

He ran for the leadership of the federal Liberals in 2008, but withdrew from the race after it became clear Michael Ignatieff would win. After Ignatieff stepped down in 2011, Rae became interim Liberal leader.

Rae told Canada AM that his decades in politics have taught him 鈥渁 lot of humility鈥� and the importance of listening to people.

鈥淚 have a lot to be grateful for,鈥� he said.