Staffordshire Police expects to make about 300 more job cuts over the next two years, it has revealed.
The force learnt it faces a 5.1% budget cut in 2010/11 and a 6.1% cut the year after, which it said was "broadly in line with our expectations".
Chief Constable Mike Cunningham said he aimed to make the job cuts, which were on top of some 280 already made, through "natural turnover of staff".
But the police federation warned frontline services could be affected.
Staffordshire Police said the cut in its government funding settlement presented a "significant challenge" but it aimed to protect services.
Mr Cunningham said: "My commitment to my staff is that we are going to work really hard to manage any reduction in our workforce through the natural turnover of staff.
"Our job will be throughout all of this to make sure that people are still safe and feel safe.
"That mission, that challenge doesn't go away because of cost and finance cuts - that mission remains critical."
The force has already cut 70 police officer jobs, five police community safety officer posts, 106 staff jobs and 100 casual and temporary positions since January.
It said this was through natural turnover and a recruitment freeze.
The force is also aiming to reduce other expenditure, such as buildings and stationery costs.
The Staffordshire Police Federation, which represents police officers, warned frontline services could be affected by the cuts.
Insp Mark Judson, from the group, said: "The federation may have a different view as to how you can possibly maintain services while reducing that number of staff".