Elizabeth May says she wants to rebuild the Green Party into an influential political force.

Three years after leaving the party's top job, May launched her bid to reclaim the leadership of the federal Greens yesterday.

She's running on a joint ticket with Jonathan Pedneault, an expert on crisis situations who has worked in war zones including Afghanistan.

May is one of two just two Greens who won seats in last year's election, following a campaign that was marred by infighting and sniping at May's successor.

Annamie Paul, who quit after the election, said leading the party was one of the worst experiences of her life.

At her campaign launch in B-C yesterday, May acknowledged the Greens have been in "disarray," and said she bears some responsibility.

Green Party members will use a ranked ballot system to choose their new leader in two rounds of voting this October and November.