More than 120 staff are facing compulsory redundancy as part of budget cuts, Derby City Council has confirmed.
Officials said 400 employees had left by 30 March as part of a voluntary redundancy programme.
But this meant a further 126 posts would be axed to achieve savings required for the coming year, part of a plan to save £25m.
Unions said the losses, which will be completed by July, would hit some frontline departments hard.
The council said it had been left with no choice but to make big cuts after its grant from central government was cut.
Charlie Carruth, from the union Unison, said the number of compulsory redundancies could still be reduced.
"We clearly said to them that they still had some time until the end of June to try and ensure as many people as possible who wanted to go went, rather than effectively dismissing them.
"I think they talked about the affordability of that and also the amount of time they had left."
A council spokesman said: "It is with regret that the council announced today that further compulsory redundancies are also necessary - the equivalent of 126 full time posts by 1 July 2011 in order to close the gap in the budget left by significant cuts to funding.
"These will be achieved through competitive restructures as agreed with the trade unions.
"The council will continue to offer those employees affected with as much support as possible during this difficult time."
Redundancies notices will be sent out from 14 April, but staff will be informed at meetings shortly.