Families who own many of Melbourne's bus services are refusing to give up their decades-old businesses, in the face of an Andrews government bid to buy them out.

A radical government plan to acquire these assets within a decade to create a state-owned public transport bus network has been rejected by nine bus consortiums.

They are refusing to sign new bus contracts, and are furious over what they describe as a government plan to "rob" them of their future business.

Andrew Cornwall, owner of Ventura Bus Company. Credit:Josh Robenstone

Industry insiders estimate that the state government attempt to take over the operators' bus fleets, depots, staff and intellectual property rights within 10 years, will cost taxpayers hundreds of millions, if not billions of dollars, as the state government pushes to modernise and improve Melbourne's bus network.