The Bloc has started making inroads into the NDP's substantial lead in recent polls, with Quebecers appearing to shy away from Mulcair's steadfast position that women should be allowed to cover their faces while they are sworn in as Canadians.

Jack Layton led the NDP to victory in nearly 60 of the 75 ridings Quebec had in 2011 as the Bloc was reduced to four seats. For the sovereigntist party to become relevant once again, it needs to win back many of those voters who turned to the NDP four years ago.

And in what Duceppe no doubt hopes become a wedge issue, he said support for banning the veil at citizenship ceremonies is overwhelming in Quebec.

"I am very much at ease with the decision of the national assembly, which is unanimous on this question," he said.

"The mayor of Montreal, the mayor of Quebec City, the mayor of Saguenay, 93 per cent of Quebecers. It is a basic question."

Besides sparring with Mulcair on the niqab, Duceppe also had a heated exchange with Trudeau on the issue.

"People are at home right now wanting to know what we are going to do to put money in their pockets, to create jobs," the Liberal leader said. "The niqab doesn't create any jobs, Mr. Duceppe."

That prompted Duceppe to fire back: "The wearing of the niqab doesn't create any jobs either."

Earlier in the debate, Duceppe attempted to portray himself as the defender of the common man as he stressed the need to increase corporate taxes on banks and oil companies.

He said the Competition Bureau should have more powers to investigate companies that hike gasoline prices, especially ahead of long weekends.

He also told the TVA-organized debate that action is necessary to rein in the rates financial institutions slap on credit cards.

One of the most amusing moments in the debate came when Duceppe twice referred to former Bank of Canada governor Mark Carney as Art Carney, the "Honeymooners" actor who died in 2003.

"Art Carney, who was head of the Bank of Canada," the Bloc leader started saying.

"Mark," corrected Trudeau.

"Mark, rather, excuse me," replied a sheepish Duceppe.

By Donald McKenzie, The Canadian Press