About 300 council jobs are being axed in Reading as part of budget cuts, a total of about 6% of the workforce.
Demonstrations took place outside a meeting of Reading Borough Council on Tuesday night, when nearly £18.8m of cuts were agreed for the coming year.
Councillors also backed plans to make cuts to adult social care and to merge some care homes.
The budget for 2011/12 will now be £124.4m, after taking into account the planned savings.
The council said this was an increase of £1.5m on the year before, but Kelvin Aubrey, of the Thames Valley branch of public sector union, Unison, said this was just a "reflection of inflation".
He said the job cuts would be a "substantial blow to the services people in Reading receive".
"We deplore the loss of jobs on that scale," he added.
The council, of which no party has overall control, said it currently had a total "headcount" of 4,915 staff, the equivalent of 3,525 full-time posts.
About 300 posts would be axed, of which about 150 are currently filled. The other 150 positions would not be filled in future, a council spokeswoman said.
The deputy leader of the council, councillor Kirsten Bayes, said key front-line areas would be invested in in the future.
"We're actually putting more money into things like learning disability and support for the elderly," she said.
"Those two together are going up by £1.7, £1.8m.
"Also we're putting additional money into child protection, so that's going up by £400,000."
The council has said it needed to save a total of about £28m over the next two years.