Two environment groups are challenging the approval for a new power station in the Latrobe Valley at the Victorian Civil and Administrative Tribunal (VCAT) this week.
The power company, HRL, applied for a 600 megawatt coal gas and natural gas power generator, but only half of the project was approved.
Environment Victoria and the Doctors for the Environment are challenging the permit in VCAT.
Dr Eugenie Kayak says the Doctors for the Environment are objecting to the project on health grounds.
"Coal combustion has adverse health effects not only through the greenhouse gas emissions, but also we worry about local air pollutants that are emitted from coal combustion," she said.
The company HRL-Dual Gas says environmental groups have no right to challenge the project.
The company's lawyer has told the hearing the actions of environment groups should be struck out because they do not have physical or financial interests in the project and emotional interests were not enough.
The legal action is expected to last between four and five weeks.
Read more about our campaign to stop HRL and new coal power for Victoria
Check out the pics from todays action at VCAT