Liberal MP Bob Rae will undertake a national campaign to sell the new Grit-NDP coalition, pre-empt his leadership rivals and outflank his current boss Stephane Dion, who could step down as early as next week, insiders tell CTV News.

While leadership contender Michael Ignatieff has taken a more subdued stance on the coalition - which also requires the support of the Bloc Quebecois - Rae has been a vocal proponent of the alliance.

"I hope we can just really engage in a discussion with Canadians about what's at stake here," Rae told CTV Newsnet Friday.

In the past few days, Conservative Prime Minister Stephen Harper has upended Canadian values and attacked the country's democratic principles through legislative maneuvering, Rae added.

Rather than facing a planned vote of non-confidence in Parliament next week, Harper instead went to Gov. Gen. Michaelle Jean and asked her to prorogue Parliament until January.

"This has all come upon us very quickly as a result of Mr. Harper's disastrous economic statement," said Rae.

The firestorm on Parliament Hill was ignited last week when the Conservatives tabled their fall fiscal update, which proposed an end to public subsidies for political parties. The opposition parties also complained that the update contained no stimulus package for Canada' struggling economy.

Rae, a former NDP premier of Ontario, said his sales job for the coalition will focus on what he calls the "politics of conviction," which he contrasted to Harper's "politics of calculation.

"We have to take positive and strong steps and we have to do it in a new way."

Meanwhile, insiders say the national tour is intended to promote Rae as a strong leader.

"It has everything to do with the leadership race," said CTV parliamentary correspondent Roger Smith. "There's this militancy in caucus, and he's sort of surfing it like a wave."

"(Rae) wants to get out there and show caucus that he's the guy that can sell this coalition and hold it together, and that sets him up as a contrast to Michael Ignatieff, who is lukewarm to the deal at best," Smith added.

Dion facing pressure to step down early

While all three Liberal leadership candidates publicly say they will support Dion until May 2 - when the Grits plan to pick a new leader in Vancouver - insiders say otherwise.

"Stephane Dion is facing increased pressure to step down as early as next week ... because he's become a liability," said Smith.

Indeed, after a dismal election result, Dion suffered yet another embarrassing episode on Wednesday, when his staff was late to deliver a taped address to the nation advocating for the coalition. When tape was finally broadcast, the video quality was blurry and amateurish.

"The question now is who would replace Mr. Dion as an interim leader. No one wants to divide the caucus or the party by having a vote inside about who would take over in the interim," said Smith.

"So hopes are that the three leadership candidates would be able to sit down and agree on an interim leader. The name most often mentioned is Ralph Goodale, who was part of negotiating the coalition. Other names include John McCallum, even Ken Dryden."

Former Liberal cabinet minister John Manley is also calling for Dion's ouster.

"As a Liberal, I believe the first step for my party is to replace Stephane Dion as leader with someone whose first job is to rebuild the Liberal Party, rather than leading a coalition with the NDP," Manley writes in an opinion piece due to be published in Saturday's Globe and Mail.

"The notion that the public would accept Stephane Dion as prime minister, after having resoundingly rejected that possibility a few weeks earlier, was delusional at best. Mr. Dion had seemed to accept responsibility for the defeat (although somewhat reluctantly), and should have left his post immediately," writes Manley.

While Ignatieff conceded on Friday that some Liberals have been talking about "accelerating the leadership process," he was candid about his own opinion on Dion.

"I can't comment on that. Mr. Dion is the leader of this party as we speak ... I'm one of the guys in the race, I don't get to make the rules," Ignatieff said on CTV's Mike Duffy Live.

Coalition cracks start to show

Earlier this week, cracks began to show in the opposition coalition and insiders wondered if the unlikely bedfellows would manage to live through to the holidays and take down the Tories when Parliament resumes in January.

"I cannot see it holding together," Liberal MP Jim Karygiannis said on Thursday, adding that Dion should also be ejected.

The coalition also has the support of the Bloc Quebecois, but with 143 seats in Parliament, the Tories would need the support of 12 opposition MPs to clinch a majority and derail the coalition's stated goal of bringing down the government.