Coderre sent a strong signal he intends to run for mayor of Montreal instead.
"It's no big secret that many people are urging me to run for the mayoralty of Montreal," Coderre said following a Liberal caucus meeting.
Although maintaining he has not yet decided whether to jump to the municipal arena, Coderre said he felt obligated to "update" his Liberal colleagues on his career plans.
He informed them he won't run for the party's leadership but will continue to serve as the MP for the Montreal riding of Bourassa until a new leader is chosen in April.
He presumably doesn't intend to formally launch a mayoral campaign until then but wanted to signal his interest now that the corruption scandal that has rocked Montreal's municipal government is threatening to force current mayor Gerald Tremblay from office a year early.
In the meantime, Coderre's decision means the Liberals, who are hanging on by their fingernails in Quebec at the moment, won't have to fight a byelection in the province until a new leader is in place.
Polls suggest the party could do much better in Quebec and elsewhere if Montreal MP Trudeau, the prohibitive favourite in the leadership contest, was at the helm.
New Democrat MP Alexandre Boulerice suggested Coderre is planning to run an unofficial mayoral campaign while continuing to collect his MP's salary.
"I think that Denis Coderre has to make a choice, right now," Boulerice said. "It would not be appropriate that the taxpayers of Canada are paying for the pre-campaign of maybe a candidate for the mayor of Montreal."
Coderre joins a long list of big-name Liberals who've declined to challenge Trudeau, eldest son of former prime minister Pierre Trudeau. Ontario Premier Dalton McGuinty has taken a pass, as has New Brunswick MP Dominic LeBlanc, interim Leader Bob Rae, Bank of Canada governor Mark Carney, former deputy prime minister John Manley and former New Brunswick premier Frank McKenna.
Since he was first elected in 1997, Coderre has been a colourful presence for the Liberal party in Quebec and one of its best organizers in the province. He has been controversial as well, quitting as Quebec lieutenant when former leader Michael Ignatieff over-ruled his choice of candidate for one Montreal riding.
Rae acknowledged Coderre will be missed but maintained there's "lots of good news" for the party in the way the leadership race is unfolding and polls suggesting Liberal support has inched up close to — or statistically even with — the NDP.
"The key thing is, there's wind in the sails of the Liberal party," he said.
The latest fundraising reports for the parties, however, sapped a bit of that wind.
Statements filed with Elections Canada show the NDP raised slightly more money than the Liberals during the third quarter of 2012 — $1.46 million versus $1.44 million. The NDP said that marked the party's best quarterly results ever for a non-election year.
The Conservatives continued to outstrip all other parties, raking in $3.4 million.
NDP Leader Tom Mulcair professed little concern about polls suggesting a Trudeau-led Liberal party would overtake the NDP, which vaulted into official Opposition status for the first time in history in the 2011 election.
"There's an old saying that a week is an eternity in politics. There are some who will have to learn that there are 155 eternities between now and the next election," said Mulcair.
Whereas the NDP is building on a strong foundation developed over the last 10 years under his late predecessor, Jack Layton, Mulcair noted the Liberals are choosing their seventh leader in nine years.
"So, I'm just going to let the Liberals sort themselves out."