Mr Madden found the project was "unlikely to have significant effects on biodiversity values" and there was "no realistic alternative alignment available" for the road.

Save Coomoora Reserve Coalition spokesman Damon Anderson said Mr Madden had ignored the community by not carrying out an EES.

"On one hand you've got all the leaders of world in Copenhagen trying to flesh out a global agreement on climate change and here at Coomoora you've got the State Government pushing through a road on what is a native remnant bushland."

The section that will be cleared for the bypass is not technically part of the Coomoora Woodland, but the flora and fauna has spread over its boundaries and onto the road reserve.

Project director Frank De Santis said VicRoads was working to "ensure the alignment will be located as close as possible to the southern road reserve boundary to minimise impact on existing vegetation".

"We will improve a large section of Coomoora Reserve by planting extra foliage and translocating some existing species.

"The Dingley arterial is a planned four-lane road extending 3.5 kilometres from Springvale to Perry roads in Keysborough.

Mr Anderson said the group had not given up the fight. "We have other irons in the fire."

Greater Dandenong councillor Peter Brown said he would raise a notice of motion at tonight's council meeting, asking the council to support a judicial review of Mr Madden's decision.