Following the revelation that a Buangor landowner is heading to the Supreme Court seeking to halt VicRoads duplication works on the Western Highway, Ms Dunn said there is a “broader” issue on whether or not original studies accurately predict environmental damage.

The landowner opposing the proposed alignment has commissioned several independent reports which raise questions over the Environmental Effects Statement used for the approval of the route by then-Planning Minister Matthew Guy in 2013.

VicRoads’ own Biosis report found the assessment of the project's impact on biodiversity and habitat flawed.

“The issue for me is that we’ve seen an enormous amount of large old trees and very large old trees go with these projects,” Ms Dunn said.

“At the core of it is that initial documentation which is proposed for the duplication is inaccurate.

“We saw the removal of far more trees at Beaufort (where VicRoads removed almost 700 more trees than expected).

“There needs to be better governance around the process, more open and transparent with local consultation. I think it’s across the board, I think it’s incumbent for government and that flows through to government agencies as well.”

The state government and VicRoads remain confident in the validity of the approved alignment.

"Since coming to power, we've worked with local community and environmental experts to ensure the final design reduces the impact of trees and vegetation as much as possible,” Roads Minister Luke Donnellan said.

"It's vital that we get on with this project which will help make this dangerous and notorious stretch of road safer for motorists every day."

VicRoads will also plant more than 12,000 trees and 50,000 other plants after construction.