Derby City Council has told staff it plans to vary the terms of their employment in a bid to help it save £32m by 2012.
In an e-mail to employees, chief executive Adam Wilkinson said the proposals could save £6.2m and up to 250 full-time posts.
It comes two months after the authority launched a three-year voluntary redundancy scheme to cut 750 posts.
But, Mr Wilkinson admitted compulsory redundancies were inevitable.
He told workers: "...if the proposals are agreed and implemented fully, compulsory redundancies could be limited to 385 FTE (full time employees).
"We are also bringing forward many of the FTE that we planned to lose over the next three years."
Trade unions have said members would not go quietly.
Derby City Council said nobody would be available to comment until Monday at the earliest.