Green Party Leader Elizabeth May says she's shocked by a decision to exclude her from the televised party leaders' debates but said she is determined to take part.

"News that I will not be allowed to participate in the debates. In shock at the moment. I will be in those debates," May wrote on Twitter.

Marco Dubé, a spokesman for the broadcast consortium that hosts the debates, confirmed the group decided unanimously that a formal proposal will only be made to the leaders of recognized parties in the House of Commons — Conservative, Liberal, NDP and Bloc Québécois.

The Green Party has yet to elect an MP to the Commons.

May was initially excluded from the debates in the 2008 election, but a public outcry forced other party leaders to agree to her participation.