Newcastle bus drivers will turn off their ticketing machines and other collection devices over a dispute with transport operator Keolis Downer regarding the company's Enterprise Agreement offer.
Rail, Tram and Bus Union members want a seven per cent pay increase over two years to offset rising cost-of-living pressures rather than over four years.
The fare free period will be indefinite, the union says, and will start at 12:01am on June 14.
The union's NSW president Daniel Jaggers said the request was reasonable given the rise in inflation but not in wages.
"Drivers are growing increasingly frustrated by this back and forth bargaining, with Keolis Downer stubbornly sticking to its initial offer. All we're asking is for them to come back to the negotiating table with a reasonable offer so members can earn a decent living wage," he said.
"The RTBU has said multiple times now that if Keolis Downer's claim that they can only pay what the government gives them is true, then minister David Elliott needs to readjust the private operator contracts to ensure members' wages don't go backwards.
"Drivers deserve to earn a decent living wage so they can live where they work. They didn't ask for the privatisation of Newcastle's bus services and shouldn't be punished by the contracts the operator is held to."
The union said in a statement it will be seeking direction from its members and cannot rule out further action should a negotiated solution not be reached.
Keolis Downer recently said the company would continue to negotiate in good faith.
A spokesperson at the time said the company believed its wage offer was fair and that it was seeking to find balance between the interests of both parties.