Member for Polwarth Richard Riordan and Member for Western Victoria Simon Ramsay say a dispute over materials could bring the $363 million project to a halt.

Mr Riordan said the contractors had indicated the project to build a four-lane highway between Winchelsea and Colac could run 10 months behind schedule if the issue was not resolved. Mr Ramsay said costs could blow out by $12 million.

The contractor requires about 400,000 tonnes of fill for the duplication works, which had expected to come from dams at properties around the Birregurra area. However, a quarry builder constructing a quarry at Birregurra has opposed the plan.

“The road contractor has requested an urgent tribunal hearing with VCAT, stating that the contractor is at risk of delivering the project some 10 months later than scheduled,” Mr Riordan said.

“Despite all the assurances we have been given from VicRoads, we are getting different information from the road contractor.

“My colleagues and I have brought the issues surrounding the Princes Highway duplication to the attention of the Roads Minister, on numerous occasions.”

“Any delay is unacceptable to this important highway construction which has huge economic value for Polwarth and south-western Victoria,” Mr Riordan said.

Roads Minister Luke Donnellan has said the duplication would be completed by mid-2019.