Compulsory redundancy notices have been sent out to staff at Greater Manchester Police (GMP), which needs to save £134m - 25% of its budget - by 2015.
Letters have been received by 156 people employed in areas including IT, human resources and catering.
A further 344 backroom posts are predicted to go by the end of May and 500 more jobs, including forensic staff and call handlers, will go by 2013.
Frontline police officers are protected by law from being made redundant.
The cuts, agreed with the Greater Manchester Police Authority and made necessary by the government spending review, mean that a total of almost 1,400 officers' jobs and more than 1,500 civilian posts will have been shed by 2015.
GMP plans to lose 94 officer posts by the end of 2012 through natural wastage and a recruitment freeze.