Tom Mulcair, Justin Trudeau confirm participation in Munk Debates

NDP Leader Tom Mulcair and Liberal Leader Justin Trudeau have confirmed their participation in a leaders' debate on foreign issues despite having raised concerns about the event'sbilingual format.

Their participation in the MunkDebatesmeans that Canadians will have the opportunity to see where the three main party leaders stand on foreign policy.

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The Conservatives had alreadyconfirmed thatStephen Harper would take part in the debate, scheduled for Sept. 28 at Roy Thomson Hall in Toronto.

RudyardGriffiths, the moderator andchair of theMunkDebates,said on Mondaythe event wouldbe broadcast in both officiallanguagesonline and onthe Canadian Public Affairs Channel (CPAC), and that the leaders could use the language of their preference at any time during the debate.

Mulcair,Trudeauin butconcerns remain

That appeared to satisfy bothMulcairand Trudeauwhoin recent days had raised questions about whether the debate would be bilingual enough to satisfy their conditions for equal French and English debates. The NDP had also noted Griffiths isn't fluent in French and questioned his ability to moderate a free-flowing bilingual debate.

Mulcair said on Tuesday morninghe would take part in the debate even if it was incumbent on him to ensure that his exchanges with the other leaders are bilingual.

"It now appears it's going to be on the shoulders of the participants to ensure that it's going to be in French," Mulcair saidduring a campaign stop inLethbridge,Tuesday, adding, "I will ensure that it will be bilingual, that the French element will be there with the rules that they've set down."

Mulcair said he still hoped to see somemoderation in both official languages.

The Liberal Party said it was confirming Trudeau's participation despite ongoing concerns over the format.

"While we continue to have concerns with the nature of the format with regards to language, there has been some accommodation," Kate Purchase, the party's director of communications, said in a news release Tuesday.

The Liberals had also raised a concern about the Munk Debates charging an entrance fee, and while the organizers did not move on thatthe party said it was "encouraged that the livestream will be available to anyone, including political parties, who wish to carry the debate."

Both leaders said they looked forward to debating such issues asthe ongoing Syrian refugee crisis.

The leaders had until noon Tuesday to formally accept the debate invitation.

Green Party Leader Elizabeth May has not beeninvited to take part in the event.

May's Greens team up with Twitter

May also been excluded from this Thursday'sdebate on the economy hosted by The Globe and Mail newspaper.

But the Green party leader plans to muscle her way into the conversation at least online with the help of Twitter.

Her party will team upwith the social media company to swiftly film and Tweet May's video responses to statements by the three invited leaders.

"This is one way of saying to Canadians, we're not going to give up on helping to communicate issues in a way that will engage voters," May said in an interview.

"It's the best we can do,"she added, "but it's far from being a fair debate."