MONTREAL - The seven candidates battling to become the next NDP leader took on a more aggressive tone in a debate Sunday, as the race entered its final stretch.

Montreal MP Thomas Mulcair, who is leading the race in terms of fundraising, faced several attacks early on. Brian Topp, Peggy Nash, Paul Dewar and Niki Ashton all targeted Mulcair during a segment where the candidates asked each other questions.

Mulcair, a former cabinet member under the Quebec Liberals, was asked about his loyalty to the NDP and whether he truly believes the party can become the next government.

Mulcair replied he believes in the NDP, but said there's nothing wrong with trying to attract new voters outside the party's base.

"People want a modern party... and that's what I propose," Mulcair said.

The debate was a homecoming of sorts for the NDP, which dominated Quebec in last May's election. The hall in Old Montreal was filled to its 1,000-seat capacity, with many forced to stand in the aisles.

The question of how to manage Quebec's place in Canada was the focus of much of the debate. "Asymmetrical federalism" -- granting Quebec a special status within Canada -- was the buzz word du jour.

Speaking to reporters afterward, Dewar acknowledged the NDP faced a difficult task in explaining the notion to the rest of the country.

"We have to take this on the road, if you will, and explain what it really means to people," the Ottawa MP said. "It's not only to ensure Quebec stays in Canada, but that we are going to be united across the country."

Nash, meanwhile, said it was important for the federal government to foster Quebec identity through art and culture, while several candidates said Supreme Court judges must be bilingual.

The French language abilities of the candidates also continue to be a sticking point. Nash asked British Columbia MP Nathan Cullen about his French during the debate.

"That's a legitimate concern that (NDP) members have raised," Ashton, a Manitoba MP who is strong in French, told reporters. "If we flipped it over, I don't think people would be OK with somebody who is not fluent in English for example."

Cullen said it's up for francophones to decide if his French is good enough, while Dewar said he's working every day to improve.

The debate, which was conducted almost entirely in French, was the second-to-last before the leadership convention.

New Democrats started getting their voting packages last week and are already eligible to mail in their ballots or vote online. The new leader will be announced at the NDP convention in Toronto on March 24.

In terms of fundraising, Mulcair has pulled in just over $205,000, compared to $182,000 for Topp, $144,000 for Dewar, $139,000 for Nash, almost $130,000 for Cullen, $57,000 for Martin Singh and $29,000 for Ashton.

Various camps say they've actually raked in more money but donations from the last couple of weeks are still being processed by the party and have not yet been reported to Elections Canada.