Quebec said the plan would still leave the province short of its Kyoto targets and demanded the country's minority Conservative government contribute around C$330 million to fund other programs.

This poses a problem for Prime Minister Stephen Harper, who says the country cannot possibly meet its Kyoto goals and promises his Conservatives will instead create a "Made in Canada" plan to cut greenhouse gas emissions.

Kyoto is particularly popular in Quebec, where Harper needs to boost support in the next federal election if he is to stand any chance of capturing a majority of seats in Parliament. The province of 7.6 million accounts for 75 of the 308 seats in the federal House of Commons.

"This is only the beginning of what could be a nightmare for Mr Harper unless he comes to his senses on climate change," Steven Guilbeault of Greenpeace Canada told Reuters on Friday.

Initial Conservative reaction was muted.

"We encourage provinces to take actions on greenhouse gases and the environment. We will be releasing a 'Made in Canada' plan in the fall," said Ryan Sparrow, a spokesman for Environment Minister Rona Ambrose.

Sparrow pointed out that Canada's 10 provinces did not have individual targets under the Kyoto deal, which obliges Canada to cut its emissions by 6 percent from 1990 levels by 2012. Current emissions are some 35 percent above the target.

Quebec has nonetheless declared that to cut its own output of greenhouse gases by 6 percent from 1990 levels it needs to eliminate almost 14 million tonnes of emissions a year. It is the first province to propose a carbon tax.

The money raised by the tax will be used to boost public transportation and fund measures to make new buildings more energy efficient.

The Quebec government said it expected oil and gas companies to absorb the tax but the industry quickly said this would not happen.

"There is no doubt that consumers will pay more," said Carol Montreuil, a spokeswoman for the Canadian Petroleum Products Institute.

Quebec also plans to limit the maximum speed for heavy trucks and bring in tougher vehicle emission standards.

Cars and trucks sold after 2010 will be held to greenhouse gas emission standards that will be roughly in line with tough California standards.