MONTREAL -- The leader of Canada's New Democrats set out to win back the hearts of Quebec voters Friday by portraying himself as a man of peace and a champion of the province's economic and social interests.

In the second of the campaign's two French-language leaders' debates, Tom Mulcair said an NDP government would hold the line on income taxes while going after big corporations to help pay for social and other programs.

Mulcair fended off accusations from Conservative Leader Stephen Harper that he would raise taxes, and from Liberal Leader Justin Trudeau that NDP promises to balance the budget would leave them without enough money to spend on necessary public programs.

In spirited exchanges, Trudeau accused Mulcair of making "bad choices" by choosing to "balance Mr. Harper's budget."

"I can assure you: I never voted for one of Mr. Harper's budgets," Mulcair responded, pivoting to accuse Trudeau of supporting the controversial Bill C-51, which expands security agency powers without oversight.

Mulcair called the law the "biggest attack on rights and freedoms" in Canada since the Liberals imposed the War Measures Act in 1970 -- something that still raises hackles in Quebec.

Appealing to the province's more pacifist preferences, Mulcair played up his opposition to Canada's role in the military mission in Syria and Iraq and his support for taking in more refugees from the Middle East.

"You've never met a war you didn't like," he said to Harper. "We need a reasoned voice for peace."

Bloc Quebecois Leader Gilles Duceppe, Mulcair's main foe in Quebec, heaped scorn on the anti-combat stance.

"We could arrive with a bouquet of flowers and a bag of groceries and say we're here to help the refugees," Duceppe taunted. "I don't think we'd be well received by the Islamists."

Broadcast by Quebec's TVA network, the debate was one of Mulcair's final opportunities to make his pitch to Quebecers, who helped propel his party into official Opposition status for the first time in 2011, mostly at the expense of the Bloc Quebecois.

Holding its Quebec constituency is crucial for the NDP if it is to have any hope of forming government after Oct. 19, but recent polls suggest that support has been slipping.

For that reason, the debate afforded Mulcair an opportunity to try to knock down Duceppe, who has called for an outright ban on wearing a niqab when giving or receiving public services -- a view many Quebecers share.

"This is a fundamental issue of equality between men and women," Duceppe insisted.

But Mulcair, who said the issue makes him "uneasy," accused Harper of trying to distract voters by legislating a ban on niqabs at citizenship ceremonies.

"You had 10 years to change this," Mulcair said to Harper. "You tabled this on the last day of the last month of your mandate of 10 years."

Mulcair also accused the Conservatives of Islamophobia -- charges Harper denied, saying it was a question of protecting "Canadian values."

Duceppe questioned whether an imminent Pacific trade deal would damage supply management -- a regime of production limits and import tariffs of vital importance to Quebec's dairy farmers.

It's an area Mulcair has tried to make his own, saying he would not honour a deal that undermines the quota system.

"Are you going to protect supply management in its entirety?" Mulcair then asked of Harper, who replied he would defend the interests of farmers.

The NDP leader went after Harper, accusing him of going to Switzerland to announce he was raising the retirement age to 67 from 65, calling it something that shows a lack of political courage and integrity. The NDP has pledged to roll back the measure if elected.

In closing comments, Mulcair spoke of 10 "bleak years" under the Conservatives. The NDP would restore Canada's place in the global community, protect the environment, and bring back services cut by the Tories, he said.

"This time there is hope," Mulcair said. "This time, we can change for good."