Union leaders have expressed shock over plans by Warwickshire County Council to axe around 1,800 staff and cut the pay of some staff.
The GMB said the cuts would be "devastating" for workers and communities.
The council said it was having to make "unprecedented" savings of up to £60 million by 2014 because of a 26% budget reduction from central Government.
"The council has predicted a worst case scenario of up to 1,855 jobs that could be at risk over the next three years, although it is hoped that the number of staff affected will be far lower," the authority said in a statement.
"The council has stressed that it will do all it can to avoid compulsory redundancies through a range of measures such as natural turnover and leaving vacant posts unfilled."
Council leader Alan Farnell said: "We know that there are going to be some difficult years and some tough choices ahead."
The GMB warned that the Warwickshire cuts would hit residential care for the elderly, people with physical and learning disabilities, cut a fifth of jobs in adult social care, the loss of the whole of the youth service and closures of libraries.
GMB officer Stuart Richards said: "The council's proposals are devastating for both council workers and the wider community.
"Our members who work in low paid, front line services are facing huge job losses and the result of these job losses will impact hardest on the poorest and most vulnerable across the county.
"Despite the Government's assurances, the impact of this will also hit services and jobs in schools."