Leaders at a G20 summit in Pittsburgh in September agreed they would submit plans to gradually cut fossil fuel subsidies as the world limited greenhouse gas emissions.

In a leaked submission to the G20 meeting in Toronto at the weekend, the government said that it had ''no inefficient fossil fuel subsidies''.

Environment groups and the Greens estimate the government hands out subsidies worth about $5 billion a year - mainly through fringe benefits tax concessions for company cars and fuel tax credits to primary producers including the mining industry.

A study in 2007 by Chris Riedy, research director at the Institute for Sustainable Futures at the University of Technology, Sydney, put the annual figure, including state subsidies, at more than $9 billion.

The government's submission to the G20 is in line with a view that the agreement was aimed at ending large, direct subsidies promoting fossil fuel production in developing countries.

It says that Australia does not have measures related to the production or consumption of fossil fuels that fall within the scope of the G20 commitment.

The Greens spokeswoman on climate change, Christine Milne, accused the government of redefining ''fossil fuel subsidy'' to avoid upsetting industry. ''Take away the fuel tax credit for the miners and see if they think they have lost a subsidy,'' she said.

The Greens leader, Bob Brown, has written to the Prime Minister, Julia Gillard, calling for legislation for an interim $23 carbon tax, later to be upgraded to an emissions trading scheme, within three months if Labor won the election.

The Climate Change Minister, Penny Wong, said the government had tried to negotiate over the Greens' proposal, but found they were not willing to consider an economically responsible compromise.

Ms Gillard told ABC radio she would have ''something to say'' about climate change before the election. ''I think there is a concern in the Australian community about what is happening next on climate change and I want to be talking to people about that.''