Nine out of 10 Unison members at Northamptonshire County Council, including social workers, are in favour of industrial action over changes to terms and conditions.
Union bosses said the withdrawal of key terms from council workers’ contracts, such as full pay for initial sick days, was “too much to bear”.
They said 98 per cent of about 1,800 members voted in a consultative ballot to reject the changes and 89 per cent wanted to take industrial action short of a strike.
Disruptive action could entail members taking public transport instead of cars to all meetings around the county, working a strict 37 hour week or not taking work home.
Steve Bennett, of Unison, said: “If it comes to taking these actions the council will come to a standstill.
“We have a very strong density of membership within social services and that is an area the county council cannot let slip at the moment.
“Ofsted will be saying in the soon-to-be-published inspection report that children’s services really need to pull its socks up. Social workers are already overloaded and shortstaffed.
“Any sort of action members take would put them in dire straits.
“These are clearly dedicated people and they would not want to do this but this issue has pushed them to this point. All their goodwill has been used up.”
About 5,000 employees are set to be affected by the changes from April 1, which is the majority of directly-employed workers, with the exception of school staff.
Unless changes can be negotiated by the unions, staff will no longer be paid for the first four days of sickness and the overall period for which they will get sick pay is to be reduced.
Other controversial terms proposed include allowing managers to send workers home if they are deemed too ill, rather than the staff member deciding themselves.
Council chief executive Paul Blantern said the measures were needed to stave off job losses and pay cuts.
He said: “The decision of the trade unions is disappointing as we believe that the proposals represent the best balance between reducing costs and protecting services and jobs.”