Train and bus workers are set to walk off the job as part of a pay dispute with Victoria's regional public transport operator.
V/Line has been notified by the Rail Tram and Bus Industry Union that operations staff will take industrial action from 3am to 7am on Wednesday, December 13.
Only non-driving grades will participate in the action, including conductors, train controllers, station and customer service staff, and authorised officers.
However, the union says it will bring the entire V/Line network to a halt.
About 93 per cent of its members last week voted in favour of taking action as workers seek a 17 per cent pay rise over four years.
RTBU branch secretary Vik Sharma said the union was focused on minimising the impacts of the action on the public, encouraging commuters to plan their working weeks accordingly.
He said the union would continue to meet with V/Line and negotiate in good faith as members would prefer to avoid the stoppage if their concerns are addressed.
"V/Line needs to stop blindly driving this corporate cowboys' train and listen to its workers," Mr Sharma said in a statement on Monday.
"We make no apologies in our fight to secure decent conditions for our members."
V/Line chief executive Matt Carrick urged the union to reconsider, declaring the planned action could disrupt tens of thousands of passengers.
The action will hit the morning peak and it will have knock-on effects for the rest of the day, he said.
"We'll continue to work with the union to deliver excellent employment conditions for our workforce and a better service for our passengers," Mr Carrick said.
"We will work hard to minimise the impacts of disruption on passengers."
V/Line is finalising replacement coaches and plans to notify passengers of the arrangements as soon as possible.
In a separate dispute, almost 18,000 officers began industrial action on Sunday after months of failed pay negotiations with Victoria Police.
Police have written slogans on their vehicles and plan to flash their lights near lucrative speed cameras to warn motorists to slow down.
Opposition Leader John Pesutto called on Premier Jacinta Allan to sit down with V/Line to sort out the "mess", as he has previously suggested she do with Victoria Police and its bargaining impasse.
"Get these two industrial disputes solved as quickly as possible as Victorians rely on these services," he told reporters.
Minister Harriet Shing said the Allan government would support talks between the union and V/Line so the parties could reach a fair agreement.
"I'm looking forward to seeing an outcome," she said.
The state government remains locked in protracted pay disputes with the Victorian branches of the United Firefighters Union and Community and Public Sector Union.
Under a state government policy, wage increases for Victorian public sector workers are capped at three per cent.
