The Victorian government says Melbourne Airport is holding a proposed rail link from the city “hostage”, with the state and the transport hub owned by some of the country’s biggest infrastructure investors now in external mediation.

The airport, which is owned by private investors including property group Dexus, IFM Investors and the Future Fund, has been locked in a stalemate with the state over the location of a train station on land leased to the airport by the Commonwealth.