MONTREAL -- There was no final show of unity in Quebec's campaign on Sunday, as the four leaders delivered contrasting final messages on the eve of the provincial election.

Rather than sticking to positive messages about getting the vote out, the leaders of the three biggest parties took the opportunity to take final shots at their opponents.

Liberal Leader Philippe Couillard declined to assess his campaign, choosing instead to denounce Coalition Avenir Quebec Leader Francois Legault, who Couillard said was "confused" on immigration.

He also accused Legault, who promised Sunday morning to support seniors, of having forgotten them throughout the rest of the campaign.

"On Day 39 of his campaign, he realized he forgot about seniors," Couillard said in Mont-Joli. "He said, 'It's true I don't have much, but oh well...oops."

Legault spent his day in the Monteregie region southeast of Montreal, where he had a testy exchange with the local Parti Quebecois candidate.

"How is it that you're against lowering taxes?" Legault asked Alain Therrien when the two ran into each other at a public event.

Therrien responded by saying he didn't believe Legault's promise to simultaneously cut spending and improve services was realistic.

"Harry Potter isn't in my party! He's in yours," Therrien shot back.

Parti Quebecois Leader Jean-Francois Lisee, meanwhile, made a visit to his hometown of Thetford Mines to visit a voter he likely doesn't have to convince: his own mother.

Andree Goulet, 84, allowed media into her home to watch her have breakfast with her son, who she said "will be the best premier."

But soon afterwards Lisee himself was on the attack, using swirling NAFTA rumours to reproach Couillard for lacking spine when it comes to defending the province's dairy industry.

Sources have said Canadian negotiators may have offered increased access to the country's dairy market as part of a NAFTA deal, something Lisee said is the equivalent of "sacrificing Quebec to protect Ontario."

He also criticized Couillard for not having a voice at the table in the negotiations, therefore leaving the province "in the dark."

While Legault called on his adversaries to refrain from partisanship on the issue, Couillard also used the premise of the NAFTA negotiations as a reason to vote for his party.

"I just want to repeat that I'll support you until the end, beyond when an agreement will be signed. I'll support our dairy producers, our industry, our farms," he said.

Sunday marks the conclusion of a 39-day election campaign distinguished by personal disagreements and generous campaign promises on how best to spend the province's billion-dollar surplus.

Heading into Monday's vote, most polls showed the Coalition Avenir Quebec with a whisker-thin lead over the incumbent Liberals, who held 68 of the legislature's 125 seats at the beginning of the campaign.

The Coalition is looking to drastically improve on its 21-seat count, while the Parti Quebecois, which formed the official Opposition with 28 seats, has remained firmly in third place.

The small left-wing party Quebec solidaire, which had three seats as the campaign began, is hoping its increased visibility and rising poll numbers will translate into a good showing.

On Sunday, one of the party's two spokespersons said she felt her party had succeeded in shaking the political establishment.

"One more legislature member, two more, 10 more, 30 more ... everything is an improvement. But sincerely I think that tomorrow, we'll really create surprises," said Manon Masse.

With files from Stephanie Marin in Becancour, Patrice Bergeron in Beauharnois, and Caroline Plante in Mont-Joli, Que.