The Green Party of Canada has filed an application with the Federal Court of Appeal to challenge a broadcast consortium's exclusion of leader Elizabeth May from the election campaign's televised leaders debates.

The party is requesting a judicial review of CRTC regulations that say the consortium of Canadian broadcasters, including CBC/Radio-Canada, is not required to include all leaders of political parties in debate programs.

On Tuesday, the consortium decided to exclude May from the English and French debates, which are scheduled to be held on April 12 and April 14 in Ottawa.

In a statement, the consortium said the decision was "based on the application of journalistic principles, and the fact that the Green Party has never elected a member to Parliament."

The consortium's initial invitation to only the leaders of the Conservatives, Liberals, NDP and Bloc Québécois triggered a fierce debate on the campaign trail over whether May should be included, as well as the consortium's control over the events.

But CBC ombudsman Kirk LaPointe said he was disappointed about the consortium's decision to limit the scope of the leaders' debates.

"I accept that this decision is not CBC and Radio Canada's alone to make," LaPointe wrote in his blog Thursday. "But it is difficult to discern how the public interest is best served by exclusion or to find congruence in the decision and the public broadcaster's mandate."

LaPointe said that while the consortium correctly noted the the Green Party does not have a sitting MP, he said logic "nestles journalistic practice in behind a political custom."

"Perhaps a shelter in a storm but hardly the best long-term mooring for the craft. These debates are journalistic creations and ought to be governed only by their best practices."

LaPointe pointed out that the Green Party garnered 6.8 per cent of the general vote in the last election. He said a party that garners one million votes can play a significant role in what could be another minority government.

"There is increased relevance mathematically, politically and journalistically to include in pivotal events any party voters have supported significantly and nationally," he wrote.

LaPointe said he decided to weigh in on the issue because his office has received more than 800 complaints about May's exclusion.

Meanwhile, May got a high-profile endorsement from former prime minister Joe Clark, who called the broadcast consortium's exclusion of the Green Party leader "unjustified and undemocratic."

"There are good arguments to change the format of these debates," Clark said in a statement Thursday. "There is no justification for an arbitrary decision to shut out a significant and legitimate political party, like the Green Party."

As for her exclusion, May said the broadcasters are trying to silence a leader who will talk about climate change, First Nations issues and foreign policy.