The CBC Pollcast, hosted by CBC poll analyst Éric Grenier, explores the world of electoral politics, political polls and the trends they reveal.

It has been a good year for the Greens, who have doubled their provincial representation and are partners in a governing agreement with the New Democrats in British Columbia.

The party began 2017 with three MLAs, one each in B.C., New Brunswick and Prince Edward Island. But after B.C.'s provincial election in the spring and a byelection victory in P.E.I. last week, the Greens now have six. Support for the federal Green Party, however, has hardly budged over that time and Green Party Leader Elizabeth May remains the sole Green MP in the House of Commons.

The Greens now appear to be having most of their success at the provincial level. Can May, who has led the federal party since 2006 and has been the MP for Saanich–Gulf Islands, B.C. since 2011, capitalize on that success to elect other Green MPs in the 2019 federal election?

And how will the debate over leaders debates, which the Liberal government is proposing should be handled by an independent commission in future elections, impact the electoral prospects of the Green Party?

Whether the Green leader should be included in the debates has been a perennial controversy. The Greens were excluded in 2004, 2006 and 2011 when the party ran full slates of candidates, but was included in 2008 — when there was one Green MP, a floor-crosser, at dissolution — and in two of the five debates held during the 2015 election.

Pollcast host Éric Grenier sat down with May to discuss the party's breakthrough at the provincial level, the challenges of translating that to federal success and what the Green Party wants to see in any future plans to institutionalize leaders debates.

Listen to the full discussion above — or subscribe to the CBC Pollcast and listen to past episodes.​

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