Former prime minister Jean Chrétien is calling Liberal MPs to urge them to support Bob Rae as interim party leader.

The former Liberal leader, who served as prime minister for 11 years, has called at least six MPs to ask them to support Rae for the job of party leader while they start rebuilding.

Rae says he hasn't decided yet whether he wants to run for leadership again. It's also not clear whether whoever fills the interim leader role can run for the more permanent leadership.

Rae says it will be easier to make a decision once the rules and criteria are clear.

"I can't say I'm a man without ambition, but at this stage in my life I am a realist about what can be done and what people are asking me to do," Rae said.

"I'm not going to go somewhere where people don't want me to go. This is something that has to be reached by consensus in the party and members of the party and members of the caucus have to feel comfortable with it."

Rae says Chrétien isn't his official agent for leadership, but he is a former prime minister who feels strongly about the Liberal Party

"I've known Mr. Chrétien for 35 years and he is a free agent. He is a man of opinions," he said.

Michael Ignatieff resigned as leader Tuesday, the day after the Liberals were reduced to 34 seats in the House of Commons. The party was forced to surrender Official Opposition status to the NDP, which won 102 seats.

Under the party's constitution, the leader's resignation triggers a leadership race with a final vote within six months. The party also has to select an interim leader within 27 days of the leader publicly resigning.

"We don't know whether the [party] executive has the power to say, well, if everyone agrees, that we won't have a trigger," Rae said.

Rae, 62, ran for leader in 2006. He also put his name up after Stéphane Dion stepped down in 2008 before withdrawing so Ignatieff could become leader without a race.

He says it's not clear whether Ignatieff has started the clock yet on the search for the new leader.

The Liberal caucus, including some of those defeated Monday night, will meet in Ottawa on Wednesday to discuss who will become interim leader.

Leader an 'internal matter': MP

John McCallum, speaking on CBC's Power & Politics Friday night, wouldn't say whether Chrétien had phoned him to talk about Rae.

"That's an internal matter for us Liberals until we emerge from our caucus," he told host Evan Solomon.

"I've been called, I've made calls, but I don't think I want to report those calls on national television."

"This is a conversation among Liberals," McCallum added.

Liberal strategist Scott Reid said nobody in an interim leadership position should be running for the permanent leadership.

"You always pick somebody who can be a trusted, even-handed person, lead the party, doesn't look like they've got their thumb on the scale for anyone, certainly isn't trying to buck to run on their own," Reid told Solomon on the Power & Politics War Room podcast

Some Liberals are worried about Chrétien's involvement because he's mused publicly about merging the party with the NDP, something many Liberals oppose, CBC's Julie Van Dusen reported. Rae is a former NDP leader and was with the NDP when he was Ontario premier.

"These men have had a long-standing relationship," she said. "They have a long history."

Talk of a merger with the NDP must also take into account whether that party, which more than doubled its seat count in Monday's election and assumed the mantle of Official Opposition, is interested.

Former NDP leader Ed Broadbent, in an interview to be broadcast Saturday on CBC Radio's The House, says he doesn't think that conversation's going anywhere anymore.

"The conversation might ... have taken place if in this election the NDP and the Liberals between them consituted a majority, i.e. Mr. Harper didn't get a majority, then there would have been a whole new scenario discussed and quite a different government might have taken shape," Broadbent told host Kathleen Petty. 

"But we are in a historically quite different position where the NDP is quite clearly dominant in numbers and I say, and have said this already to some in the Liberal Party who are social democrats, that now's the time to join the NDP."

Other MPs being discussed as candidates for interim Liberal leader are Ralph Goodale and Wayne Easter, neither of whom speak French, and former astronaut Marc Garneau.