The federalist victory in Quebec on Monday not only quieted the sovereignty debate, but created the favourable conditions Prime Minister Stephen Harper needs to call a spring vote, say analysts.

The Parti Quebecois placed third in the provincial election -- a historic low for the party -- effectively stopping the clock on any timing for another sovereignty referendum.

The narrow win by Jean Charest's Liberals, combined with the stunning increase in support for Mario Dumont's right-of-centre ADQ party, translates into an "unconditional win" for the prime minister, said CTV's chief parliamentary correspondent Craig Oliver.

"(Harper) had two horses in this race -- and they both won," he said.

The federal Conservatives now have more ideological allies than ever in Quebec, thanks to 41 members elected under the nationalist, populist ADQ banner.

The party's rise is a vindication of Harper's policy of accommodation towards Quebec, said Oliver, adding that given these results, a federal election this spring seems almost certain.

"Harper is in a position where his policy of accommodation has caused a vast majority of Quebecers to vote for the present constitutional arrangement and rejected the vision of Quebec espoused by Rene Levesque 30 years ago; that is: independence," said Oliver.

Analysts have been predicting that a slight Liberal majority or Liberal minority, with the ADQ holding the balance of power, would mean the Tories would be looking to call an election sooner than later in order to capitalize on federalist momentum -- at the expense of the Bloc Quebecois.

Harper has been pledging a more open federalism over the past year, and has invested heavily in boosting Conservative support in Quebec.

His long list of initiatives in the province include millions of dollars to fight climate change; a pledge to recognize the Quebecois as a nation; and a promise to give Quebec a semi-formal role in international affairs.

And in the final stretch of the election campaign, Harper gave billions of dollars in transfers to Quebec. Charest used the gift from Ottawa during the campaign to remind Quebecers why it's best to vote for a federalist government.

Charest was polling more than 20 points behind his separatist rivals at various points since the 2003 Quebec election, but Tory promises helped resuscitate his political prospects.

But observers say there's little doubt Harper was also watching the rise of Dumont and the ADQ in order to gauge the strength of Quebecers' support for a conservative point of view.

ADQ voters, Oliver said, are largely made up of small-c conservatives when taken to a national level. And most of the 10 seats in Quebec that Harper won in the last election were in the Quebec City-area ridings where the ADQ is strong.

"These votes in Quebec tonight translate probably into a minimum of 40 (seats) for Stephen Harper and the Conservatives in the next federal election," said Oliver.

Quebec has 75 seats. The Bloc won 51 in the last election and the Liberals 13.

Their promise to butt out of provincial business and transfer money to the provinces was a key reason for Conservatives' electoral success in Quebec, where their gain of 10 seats helped them form a minority government in the last federal election.

Leadership questions

Antonia Maioni, a political science professor at McGill University, says the PQ's third-place finish puts leader Boisclair's job in jeopardy.

"There's going to be a lot of change in that party, and I think the change is going to start with Andre Boisclair probably stepping down at some point. He will take the fall on that," she told Canada AM Tuesday morning.

CTV's Jed Kahane, reporting from Sherbrooke, Que., says there's little doubt that Boisclair will have to step down "in the not-too-distant future."

"He had one chance to bring the PQ up; instead their numbers sank to historic lows. So Boisclair is going to be replaced," Kahane said.

Maioni added that Jean Charest, who barely held onto his own riding, may also take the fall inside the Liberal party.

"The Liberal party was not able to get very far with the francophone vote. In fact, the ADQ now has more francophone votes than any other party in Quebec. And so that is certainly a message to Jean Charest. He will be leading the government but he's in a very weakened position. And he may be also considering his political future today."

"I think there's going to be a lot of pressure on him to reconsider his political future," agreed Kahane, "maybe not in the coming weeks but certainly by the time the next election rolls around."

Indeed, Charest conceded in this speech Monday night that he has heard the message from voters loud and clear.

"Today Quebecers delivered a judgment, a severe one, and the Liberal party and I will have to learn lessons from it,'' Charest told his supporters in Sherbrooke, Que.

Maioni adds that the Liberals will have to make some concessions to make this minority government last.

"If the Liberal party wants to remain in power, it's going to have to start listening to the ADQ and moving its agenda to the right as well," Maioni said.

"[Charest] just needs to make sure that he keeps the ADQ happy. And that will probably be the key to his political future."

With files from The Canadian Press