About 130 Nottinghamshire Police officers could now be made to retire early because of cuts to the budget.
Initial estimates said that about 90 staff with 30 years' service would be asked to go as part of plans to save £46m (22%) over the next four years.
About 100 other staff have already been told they are at risk of being made redundant.
Nottinghamshire's Deputy Chief Constable Chris Eyre said every option had been explored.
He said: "We will do everything we possibly can to protect the employment of the people who work for us.
"We've been root-and-branch through the organisation to try and find ways that we can take cuts out without going near staff - so we've looking at every single infrastructural cost that we've got.
"But ultimately, to be able to take out that kind of saving from an organisation which is 85% staff-based, means that we've having to get into making difficult decisions."
A restructuring process is already underway and formal consultation with police staff and Unison over stage one of the restructuring plans began on 27 January.
Jon Collins, chairman of Nottinghamshire Police Authority, said: "Police performance in Nottinghamshire is going from strength to strength and we have recently recorded some of the lowest levels of crime in the city ever, as well as rising detection rates.
"There is, however, more work to do and this must now be undertaken in a climate where there is significantly less funding available to invest."
Critics have said losing experienced officers was a short-sighted move.