Western Metropolitan Region MP Colleen Hartland said the proposed Outer Metropolitan Ring Road would not solve the traffic woes plaguing outer suburbs residents, including those in Sunbury and Craigieburn.

"By the time they start construction of this project in 2020, petrol will be so expensive. They would be better off putting the money into public transport," Ms Hartland said.

"The Outer Ring Road wasn't in the Government's transport plan, which they claimed was a comprehensive strategy to 2020 and beyond," she said.

"Reports that the Outer Ring Road will run through significant grasslands and other native vegetation are a concern."

The Property Council of Australia's Victorian division executive director Jennifer Cunich said her organisation supported the urban growth plan and transport links but would not support the GAIC.

"How this infrastructure is funded is proving to be the sticking point," Ms Cunich said.

"The Property Council cannot support the GAIC in its current form. We need more detail about how this charge will be implemented to enable us to assess the impact on the housing industry, housing affordability and the local community."

Liberal Northern Metropolitan Region MP Matthew Guy said the GAIC was unacceptable in its current format.

"It's nothing more than a greedy tax grab from a government that's broke.

"We support a developer contribution and think it's ludicrous that landowners should pay."