Federal leaders' French-language debate: 5 elements to watch for tonight

Tonight's French-language debate may not get the same attention outside Quebec as the previous debates, but it could still prove influential on the outcome of the election.

"This debate matters, because if there's ever a shot at breaking the NDP stranglehold on Quebec voter love right now, this is it," said David McLaughlin,the former chief of staff to Brian Mulroney. "If the NDP loses ground in Quebec, then there's no way they can form a minority government."

TheNDP continues to lead in the polls in the province, where it held 53 seats before the dissolution of Parliament, followed by the Liberals with seven, the Conservatives with five and the Bloc Qubcois with two.

Here are five things to watch for in the debate, the first to feature all five party leaders:

1. EnterGilles Duceppe

This will be the first time in the campaign the Bloc leader has participated ina leaders'debate, and with his party on political life-support, it could be his last chance to make a majorsplash in the province.With nothing to lose, and as the headof a party with only two members of Parliament, expect Duceppe to come out swinging.

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How to watch Thursday's debate

The French-language leaders' debate will be broadcast live andlivestreamedonline 8 p.m. to 10 p.m. ET Thursday.

You can watch the debate in simultaneous English translation on CBC News Network and online atCBCNews.ca/Canada Votesbeginning with a Power & Politics pre-debatespecial at 7 p.m. ET. The debate will be broadcast in French by Radio-Canada (check local listings) andlivestreamedonline atICIRadio-Canada.ca.

The debate is being produced by a partnership of Radio-Canada, La Presse, Tl-Qubec, CBC News, CTV News and Global News, together with Facebook, Instagram, Twitter, Vine, Google,YouTubeand CPAC.

2. TheMulcair/Duceppeshow

And who exactly willDuceppebe swinging at? One would normally think the prime minister would be the focus ofany kind of debate.Buttonight,Conservative Leader Stephen Harper may just stand back, try to look prime ministerial, and watch the others attack the main target NDP Leader Tom Mulcair.

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• Duceppe likely to target Mulcair in French-language leaders' debate

Liberal Leader Justin Trudeau will try to get in his shots, said ChristianBourque, executive vice-president ofLgerMarketing."I think theMulcair/Duceppeduel will be the main feature of the debate."

All the leaders willtake turns aiming shots at Mulcair, butexpect Duceppe to be the most aggressive, challengingMulcair onanumber of issues including the niqab, daycare and pipelines.

3. Speaking of the niqab

It's one of those hot-button wedgeissues whethera woman should have the right to wear a niqabwhile taking the oath of citizenship but it's still unclear whatinfluence it will have on voting decisions. Still,Duceppehas come out strongly against it, saying he'd be infavour of invoking the notwithstanding clause in the Charter of Rights and Freedoms to ban the wearing of aniqabduringthe oath.

"Why Gilles Duceppe will want to use that againstTom Mulcair in [tonight's]debate isbasically because it makes the NDP look to be in contradiction with what the Bloc would say is the will of Quebecers," saidBourque.

In a speech in Montreal on Wednesday, the day before the debate,Mulcair clarifiedhis stand, sayinghesupports the current requirement that women show their faces at some point in the citizenship processbut that they should not be forced to remove a face covering while taking the oath of citizenship.

"If youare Tom Mulcair, you want this not to be the main focus of the debate. So by giving out whathis position is, and clearly stating what his position is he'll be able to say, 'I've said it clearly, here's how Ifeel about it, I've said it yesterday, there's no more to add."

4. Energy East pipeline

The proposed 4,600-kilometre pipeline would carry 1.1-million barrels a day ofoilsandscrude from Western Canada to refineries in Quebec and New Brunswick. But it's become acontroversial issue in the province,withconcernsthat the pipeline carries ecological risks. It was talked about briefly in the first debate,whereTrudeau accusedMulcair of flip-flopping, while Harper accused Trudeau of the same.

This time, Duceppe, who opposes the plan, gets to weigh in, and he will likely focus onMulcair, accusing himof supporting the pipeline when speaking to the West,but opposing it when in Quebec.Mulcair hassaid the pipeline should not beapproved without a thorough and credible environmental evaluation, but that the notion of bringing oil from West to East could "accomplish a lot of positive things."

5. Policy plugs

As withthe last debates, expect all leaders to plug policies they think would play well for aQuebec audience. For example, Trudeaumaytalk aboutscrapping the plan to buyF-35fighter jets and his announcement this weekto boost spending for the arts. Harper mightremind viewersthat his government would makeQuebec's Collge Militaire Royal de Saint-Jean a degree-granting military university. Meanwhile, Mulcair will boast that his national daycare plan is patterned after Quebec's.