OTTAWA -- The Liberals are promising a "very strong, vigorous race" for the party leadership.

Liberal deputy leader Ralph Goodale brushed off questions Monday that the contest was slow to get off the ground, saying judgements so early in the contest would be "jumping the gun."

The top job has been vacant for 15 months so far, and it's been three months since interim Leader Bob Rae confirmed he wasn't seeking the role on a permanent basis. So far, no Grit MPs or star candidates have thrown their hats into the ring, but Goodale maintained interested MPs are "keeping their powder dry for the time being" waiting for the five-month race to officially kick off in November.

"Which from a caucus point of view is probably an appropriate strategy," he said. "But the names will come forward this fall."

Goodale also noted any MPs who step up to the plate will continue to actively participate in their responsibilities in the House.

"We don't want to bench our strength," he said.

Candidates will face a series of debates and a preferential vote before the race wraps up at an event in Ottawa on April 14.

MPs who have mused about running include Marc Garneau, David McGuinty and Dominic LeBlanc. Failed 2006 leadership candidate Martha Hall Findlay has also said she's eyeing another bid.

But the biggest name could be that of Quebec MP Justin Trudeau, who is widely believed to be ready to step into the ring despite maintaining he's uncommitted.

For his part, Garneau kept mum on whether he's concerned the contest will turn into a coronation if the son of former prime minister Pierre Trudeau decides to run for the leadership.

"I hope Justin is in it, and I will announce whether I'm in it in due course," he said.

The Liberal Party, meanwhile, touted the 20,000 Canadians who signed up as so-called Grit supporters over the summer as an example of the interest the race is garnering across the country. Supporters don't pay for a party membership but can still cast a ballot for the new leader.