Coalition Leader Francois Legault says the Quebec Liberals won the provincial election because of the omnipresence of threats of a sovereignty referendum.
Legault's party won 22 of the province's 125 seats Monday — just eight fewer than the Parti Quebecois.
Philippe Couillard's Liberals stormed to a majority victory with 70 seats after he focused their campaign on the danger of another referendum in the event of a majority PQ government.
Legault, a former PQ cabinet minister, insisted he will be around for the next four years.
"I want to build a credible, responsible and constructive alternative to the Liberals in every region of Quebec before the next election in October 2018,'' he told a news conference in Montreal.
Much of the Coalition's strength is limited to a few areas in the province, particularly on the north and south shores of Montreal.
Legault said he believes the referendum issue was the catalyst behind the Liberals' victory.
"I don't think it's healthy for one political party to be able, almost automatically, to take power without really proposing anything,'' he said.
"The omnipresence of a referendum or sovereignty allows the Liberals to win elections without too much effort.''
Legault added that Couillard needs to work on bridging the gap in terms of wealth between Quebec and the rest of Canada.
"It's a question of pride.''
The crushing PQ defeat led leader Pauline Marois to announce in her speech Monday night she was quitting politics after a career that spanned more than 30 years.
Her announcement triggered immediate speculation as to who will eventually succeed her, with much of the attention turning to media baron Pierre Karl Peladeau, who won his seat in Saint-Jerome.
But the star of the night was undoubtedly Couillard, one of the most federalist Quebec leaders in years.
He sent the PQ to one of its worst electoral defeats by successfully exploiting Quebecers' distaste for a third referendum in a nasty campaign that voters complained didn't focus enough on bread-and-butter issues.
Couillard, a popular health minister in Jean Charest's government until 2008, presented himself as a uniter when he addressed ecstatic Liberal supporters late Monday evening.
"We are all Quebecers,'' he said in his victory speech in his Roberval riding, which he captured from the PQ. "We should all focus on what brings us together.
"Let us say together, with passion, we're all proud of being Quebecers. My friends, division is over. Reconciliation begins.''
Marois called the election on March 5, hoping to win a majority based on a campaign of identity politics anchored in its controversial secularism charter, which would have banned public-sector workers from wearing such religious garb as kippas and hijabs.
But Peladeau's campaign launch just a few days later derailed the majority scenario when he delivered an enthusiastic, fist-pumping endorsement of an independent Quebec.
The PQ never recovered even though Marois insisted over and over there would be no referendum until Quebecers wanted one.
In terms of popular support Monday, the Liberals pulled in 41 per cent, a dramatic climb from 31 per cent in 2012. And the PQ finished the night with about 25 per cent, just two percentage points more than the Coalition.
Marois's defeat follows the crushing of the Bloc Quebecois in the 2011 federal election when it was reduced to four seats. It is stunningly similar to one that brought her to the PQ's top job after Andre Boisclair suffered one of the worst electoral thrashings in the PQ's history in 2007.
Marois won fewer than the 36 ridings he claimed.
When Marois called the election, the PQ had 54 seats, the Liberals 49, the Coalition 18 and Quebec solidaire two. There were two Independents.
Voter turnout on Monday was 71.5 per cent, compared with 74.6 per cent in 2012.