Elizabeth May is not letting the lack of an invitation keep her out of Thursday's election debate on the economy.

The Green Party leader plans to muscle her way into the conversation, at least online, with the help of Twitter.

The party is teaming up with the social media company to swiftly film and Tweet May's video responses to statements by the three invited leaders.

The Globe and Mail newspaper has asked Conservative Leader Stephen Harper, NDP Leader Tom Mulcair and Liberal Leader Justin Trudeau to discuss economic issues Thursday evening at Calgary's Stampede Park.

May and her team will be hunkered down in a Victoria church with Twitter's Steve Ladurantaye, creating a steady stream of video remarks, retorts and reality checks.

People watching the debate on the Canadian Parliamentary Affairs Channel or at globeandmail.com won't see or hear May.

But the idea is to engage Canadians following the debate on Twitter, including many who will have their TV remote in one hand and their smartphone or tablet in the other.

"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.

In past elections, the English and French TV debates organized by leading broadcasters have been key campaign events. But this time the English one might not even happen. At the same time, several privately sponsored exchanges are taking place.

May's gritty performance in an August debate hosted by Maclean's magazine earned her plaudits and valuable attention for her effort to expand the party's foothold of two MPs.

The Greens have denounced May's exclusion from the Globe and Mail event, an exchange staged by the Munk Debates in Toronto on foreign policy, and a French-language debate on TVA.

Sean Humphrey, the Globe and Mail's vice-president of marketing, has defended the Calgary format, saying it will "lead to focused discussion on the Canadian economy."

The exclusion led Twitter's Ladurantaye, a former Globe and Mail reporter, as it happens, to suggest a parallel digital debate, an approach he took in Britain last March with the Scottish National Party.

"You don't need to wait to be invited to something anymore. If you want to be part of it you can be part of it," Ladurantaye said. "Because there's this whole conversation that's going to be happening that night on Twitter."

He points to new figures that suggest almost 60 per cent of Canadian Twitter users were unsure of who they would vote for in the election.

Twitter is working with all five leading parties on different facets of their campaigns, Ladurantaye said.

The Greens wanted Twitter's expertise and on-site assistance to make sure "we're doing the technology side of this right," said party communications director Julian Morelli, adding the company is not charging for its services.

The party hopes a crowd of Green supporters will be at the Victoria venue to watch large screens, one showing the Globe debate, the other projecting May's Twitter feed.

May, meanwhile, will be in an adjacent room watching the debate and preparing her video responses.

She would consider it party crashing if she turned up in Calgary and banged on the door to get in.

"I'm not the kind of person to do that. But using social media and smart technology to give Canadians an additional option in the way they access this debate, I think is completely appropriate," she said.

"The disadvantage is, I'll get 30 seconds to insert what I would have said. Even using social media as cleverly as we possibly can, nothing replaces being on the stage to say, 'But wait, Mr. Harper ...'

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