Liberal Leader Philippe Couillard accused his Parti Quebecois counterpart, Pauline Marois, of failing to come clean with Quebecers on the referendum issue.
Polls repeatedly suggest that a majority of Quebecers do not want a plebiscite and Couillard's strategy was similar to his approach in last week's debate: try to cast the PQ as a party that fosters political uncertainty at the expense of economic prosperity.
"People know you're going to have a referendum," he said in a heated exchange with the premier.
Marois countered with the argument she repeatedly used last week — that there will be no such vote until Quebecers are ready for one.
"The election is all about choosing a government," she said."
"You know very well, Mr. Couillard, that I am a determined woman but that I am a woman who can listen to Quebecers."
Couillard reiterated the Liberal mantra that Quebecers don't want a referendum and that their priorities are jobs, health care and education.
That prompted Marois to accuse her rival of being soft on the national question.
"Yes, Quebecers want jobs but they also want a Quebec that stands up for itself."
Francoise David, whose leftist Quebec solidaire is staunchly sovereigntist, mocked Coalition Leader Francois Legault on the former PQ cabinet minister's position on the national question.
"Are you still a sovereigntist who doesn't dare say so, or are you a federalist who is a bit embarrassed?" she asked him.
Legault's response was the following: "I am a nationalist. I believe in Quebec first and foremost."
With an opinion poll this week suggesting the Liberals were leading in popular support, Marois, Legault and David made a point earlier in the debate of ganging up on Couillard on integrity issues.
Couillard was grilled extensively about his ties to Arthur Porter, a former hospital administrator who now faces fraud charges in connection with a scandal-plagued contract to build a large Montreal hospital.
He and Porter were appointed by Prime Minister Stephen Harper to the committee that monitors Canada's spy agency, and they also ran a consulting business together.
Couillard took issue with being mentioned in the same breath as Porter.
"He's someone I knew but to associate me in any way whatsoever with what he's accused of doing is unacceptable, unacceptable," the Liberal leader said.
"I wasn't even around him when the contract was handed out."
David then went after Couillard following a Radio-Canada report that he placed $600,000 in an offshore tax haven while practising as a neurosurgeon in Saudi Arabia well before embarking on his political career.
Couillard repeated there was nothing illegal about the account at a branch of the Royal Bank of Canada based in Jersey, in the Channel Islands between England and France.
"I respected all the tax laws," he said. "Upon my return to Canada, I paid all the requisite taxes."
Couillard was also challenged on a report that $428,150 in Liberal party financing is still unaccounted for.
"It doesn't exist," the Liberal leader said. "There is no fundraising event that can raise such a sum."
Marois had to deal with integrity issues of her own amid boasts that her government has attacked corruption since coming to power 18 months ago.
The PQ leader was questioned about possible dealings between her husband, Claude Blanchet, and the province's largest labour federation.
The controversy revolves around a 2009 wiretap that was played recently at the provincial corruption inquiry and that hints at an arrangement between Blanchet and the Quebec Federation of Labour.
The recording captures Michel Arsenault, who was then president of the labour federation, saying he was ready to enlist the aid of the PQ to help thwart a corruption probe and that the labour union had a "deal with Blanchet.''
"The PQ won't touch this,'' Arsenault is heard telling another union boss. "I'll talk to Pauline.''
Marois was in opposition at the time of the recording.
She told the televised debate what she has repeated over and over since the testimony: there was no deal.
"Mr. Arsenault told the Charbonneau Commission that when he met me, he ran into a wall, a brick wall," she said. "I can assure you that there was no deal."
In her post-debate news conference, Marois acknowledged that Couillard was the main target in the two-hour event.
"It was normal tonight for him to have all the questions or some attacks," she said. "But I don't think I attacked him more than I attacked the positions of the other people around the table."
Legault repeated his debate comments that Couillard is resorting to scare tactics by constantly mentioning a referendum.
"I'm talking about courage, not about fear," he said. "Mr. Couillard is talking about fear. I am talking about courage. I think Quebecers are courageous people."
But Couillard didn't back down on the matter when he addressed reporters.
"On the referendum question, it's clearer than ever for me that there's going to be one because she (Marois) wasn't able to dissipate the doubt."