The TSSA has accused the train operator of a “criminally negligent” shortage of the specialist role, which it says is jeopardising security on the network. ScotRail said the changes would improve safety on the railways.
The union said there had been “bad management” of a company-wide voluntary severance programme after it accepted applications from 17 of 22 specialist staff.
TSSA general secretary Manuel Cortes said: “ScotRail bosses are keen to cut salary costs, but as they do so they show they know the price of everything and the value of nothing.
“They are purposely undermining the safety critical aspect of their own CCTV operation as they implement their misguided and dangerous cuts agenda.”
ScotRail sustainability and safety assurance director David Lister said the company was “disappointed” by the vote, but would continue discussions.
He added: “The vast majority of our employees are very positive about the investment we are making. The safety of our employees and customers is our priority ... it is wrong and misleading to suggest otherwise.”