VICTORIA -- Elizabeth May says the Greens are about to lay out a battle plan to fight climate change as Canadians participate in the most important election in the country's history.

The Green party leader told about 200 cheering supporters at her campaign launch in a Victoria hotel that her party will stand firm on its climate values, which include banning new pipeline projects and working to transform Canada's economy to generate and use renewable energy.

"This election is about telling the truth to Canadians about how serious the climate emergency really is," said May. "We do that ... not to create fear. We have a plan. We know this is a climate emergency. How could we have Parliament pass a motion June 17 saying that we're in a climate emergency and the next day our government committed to spend $13 billion to buy the Trans Mountain pipeline?"

The pipeline-twinning project from northern Alberta to Burnaby, B.C. is expected to be a campaign issue even though the two major political parties, Liberals and Conservatives, support its construction.

The federal government under Justin Trudeau announced plans to buy the pipeline project for $4.5 billion at the end of May and gave it cabinet approval June 18. Carrying out the expansion project could bring the total cost to $13 billion, though the Liberals' stated intention is to sell it back to the private sector after it's passed through more approvals.

"We will hold the line," said May, who was arrested during an anti-pipeline protest in B.C. "No one can dissuade us from seeing clearly that we need to move away from fossil fuels as quickly as possible. That's our Mission Possible."

May's campaign launch also touched on the issues of abortion and Quebec separatism, which have been the source of party controversy lately.

She said the Greens won't run candidates who do not support a woman's right to choose to have an abortion, and supporters of Quebec's separation from Canada will also not be permitted to run for the Greens.

May placed her right hand over her heart and said the Greens will never waver on support for legal, safe abortions for women.

"We will not let candidates break a sacred pledge," she said.

May made similar vows to ensure separatist candidates do not run for the Greens.

"We will not have a candidate who thinks they can work to break up our country," May said.

She said climate change will be a dominant issue throughout the campaign because Canadians want a clean and bountiful home for their children and grandchildren.

"Nothing matters more than ensuring our children and grandchildren can live out their natural lifetimes in this beautiful country," May said.

May was joined by B.C. Green candidates, including her husband John Kidder and Paul Manly, who is seeking re-election after winning a Vancouver Island seat in a byelection last spring.