Regional train passengers will be left stranded as V/Line employees take industrial action in the coming weeks.
The Rail, Tram and Bus Union announced V/Line employees will take industrial action from January 29 after negotiations for a new agreement still unresolved.
It follows industrial action in December that saw trains cancelled on every regional train line for one day.
Industrial action will begin with a 24-hour stoppage on the Geelong and Warrnambool lines on Wednesday, January 29.
The Bendigo and Swan Hill line will see a 24-hour stoppage on Friday, February 7.
Action will also include an indefinite ban on working overtime on Mondays and Fridays from January 31.
Negotiations for a new agreement for V/Line workers have been held since January, 2019.
RTBU Victorian branch secretary Luba Grigorovitch said negotiations with with V/Line were going in circles.
"We're not getting anywhere, we need a circuit breaker," she said.
"We're trying to find middle ground but V/Line have demonstrated they are unwilling to compromise.
"We don't take any action lightly and ultimately would prefer it be avoided, but RTBU members are fed up and the public deserves a way forward."
The RTBU says ample notice of industrial action has been given for progress to make sure the state government wish to avoid the industrial action.
It has also called for a third-party mediator to be appointed in an effort to progress negotiations.
A government spokesperson said Department of Transport and Australian Open are working to reduce the impact as best as we can and will keep passengers informed.
"This is an incredibly disappointing decision, especially during the peak of our major events season," the spokesperson said.
"There is still time for the parties to resolve this without impacting Victorians who rely on these services to get them where they need to go."
V/Line chief executive James Pinder said he hoped to minimise the impact of any industrial action may have on passengers.
"It's extremely disappointing and frustrating that the RTBU has decided to once again take this unnecessary action. Our passengers don't deserve to be bear the brunt of this decision by the RTBU," he said.
"Discussions with the RTBU took place as recently as last week, making this decision by the RTBU even more frustrating given talks have only just resumed for this year. We want to move forward with these discussions and urge the RTBU to do the same.
"We will be doing everything we possibly can to minimise the impact of protected industrial action, to help ensure our passengers can continue to get where they need to go and sincerely thank them for their patience and understanding during this challenging time."