Staff at Derby City Council are to take industrial action on 9 June in a row over travel allowances.
Council staff who use cars for work are currently given £1,000 a year plus mileage allowances, but now some say they will refuse to use their own cars.
The council has said it is to scrap the payments and replace them with a flat fee of 40p-a-mile.
Conservative councillor Sean Marshall said the council was taking action because it needed to cut costs.
"We have to cut our cloth accordingly - we have all got to cut costs," he said, adding he hopes the action will not have any impact on frontline services.
He said the council would have 50 pool cars on standby for staff to use so services would not be affected.
The Unison union, which represents some of the workers, has said it expects the action to disrupt some key council services such as social care.
The action will continue until the council agrees to come back to the negotiating table, a union official said.
The union also said the money was a vital part of the jobs package.