Dr Flannery's call comes as public opposition mounts against the proposal to build a 600-megawatt plant in the Latrobe Valley.
As of last week, the Environment Protection Authority had received more than 4000 submissions on the project, most of them objections. The authority said it had never received so many submissions for a project under assessment.
Dr Flannery told The Sunday Age the future of coal was uncertain and the plant would be a $750 million waste of money. He said if the power station was approved, voters would not trust Mr Brumby's recently announced target to reduce emissions by 20 per cent by 2020.
''We've already seen the Howard government fall over on the climate change issue, we've seen Kevin Rudd lose his prime ministership over it and we've seen Malcolm Turnbull deposed,'' Dr Flannery said.
''This is not an issue that politicians can dodge. Premier Brumby will have zero credibility in the environmental area without dealing with this issue before the election. If he doesn't, every environmentalist and voter will look sceptically at his target.
''You can build as much solar as you want, but if you build new brown coal power plants you will not reach your target,'' Dr Flannery said. ''This is a grossly polluting plant and it will be around for 50 years.''
The proposal is being put forward by Dual Gas, a subsidiary of Melbourne company HRL, which is teamed with the state-owned China National Electric Equipment Corporation. Dual Gas says its new gasification technology will mean the plant is a third less polluting than Victoria's existing brown coal generators.
But environmentalists say it is still too polluting and Victoria should not be building any more brown coal power stations. The government recently announced a pollution limit on new power stations – 0.8 tonnes of carbon dioxide per megawatt hour of electricity.
Dual Gas resubmitted its application to the EPA after it was told it would not meet the new limit.
The company now says the plant's average intensity is between 0.73 and 0.78 tonnes per megawatt hour, although Environment Victoria says Dual Gas has failed to include the emissions associated with the energy use of the coal-fired power station itself.
The average emissions intensity of power plants in the OECD is 0.45 tonnes.
Environment Victoria wants Mr Brumby to withdraw the $50 million of taxpayer funds he has committed to the project – which failed to meet its original construction deadlines – and hold a public consultation process, as he committed to in Parliament, on whether 0.8 tonnes of carbon dioxide is an appropriate limit.
Mr Brumby's spokeswoman Fiona Macrae said the EPA process was independent.
''The government is confident of meeting its target to cut emissions by at least 20 per cent by 2020, irrespective of whether the EPA approves the HRL project,'' she said.
We also were responsible for a few thousand of the objections to this proposal. Check out the online petition here