TORONTO - A Green government would bring the "voice of reason" to Ottawa, leader Elizabeth May said Thursday as she unveiled an election platform that promises to overhaul Parliament, jack up corporate taxes and legalize marijuana.

The fully costed platform includes an additional $3.8 billion in spending, financed by a spike in corporate taxes and an end to subsidies for nuclear and fossil fuels -- moves worth $6.5 billion a year.

May billed the platform as a sensible and practical alternative to the status quo, a holistic vision of government that confronts Canada's future challenges, both economic and environmental.

"Our goal is to be that voice of conscience, that voice of reason," she said during a news conference in Toronto -- May's first sojourn outside B.C. since the start of the election campaign.

"Failure to address significant threats to our future is irresponsible," she said. "We will come up with significant solutions and our voices ... will make a difference."

The party is focused on three major themes, May said -- a "smart economy," "strong communities" and "true democracy."

The platform calls for income splitting for all Canadian families including same-sex couples, investment in early childhood education, tax credits for students and a boost for municipalities.

May promised to introduce her income-splitting scheme immediately, rather than wait for a balanced budget four years from now, as the Conservatives have promised.

"We've been advocating full income splitting for Canadian families since the 2008 election; we're the only party that's done that," she said.

"There are a lot of circumstances in which you need to give families flexibility."

There's $1 billion to help municipalities launch a youth employment program that would hire students to work on city projects for a year for minimum wage. Each student would then get a $4,000 tuition credit at the end of the program.

The Greens would also create six "superfunds" to help municipalities pay for community housing, environmental remediation, water and waste treatment facilities, sports and recreation facilities and for efforts to promote mass transit and cycling.

"This is the strongest commitment to municipalities you'll ever see in any platform from any party," May said.

The party would implement carbon pricing to offset reductions to Employment Insurance and Canada Pension Plan contributions and the elimination of personal income tax for anyone earning less than $20,000.

The Greens plan to raise corporate taxes to 19 per cent, up from the current rate of 16.5 per cent.

They would also cancel a series of tax credits for logging and mineral exploration and close tax haven loopholes.

The three-year budget also includes:

  • $2.5 billion over three years to establish national affordable housing program;
  • $150 million per year to retrofit municipal, university, school and hospital facilities;
  • $1 billion per year on electrical grid updates;
  • $2.5 billion in added revenue over three years from legalizing and taxing marijuana.

May conceded that her party is not in a position to form a government, but said she still plans to fight for a spot in the televised leaders' debates.

"It's clear that many things we talk about in this platform will simply not come up in the debates if we're excluded," she said, noting there were no questions on climate change in the 2006 debates.

The party failed to secure a seat in the 2008 federal election, but drew nearly 1 million votes.