Staff at Hampshire's police control centre have requested a strike ballot
Staff at Hampshire Constabulary's control centre have threatened strike action over changes to work conditions.
Unison, which represents employees at the centre, has been asked to ballot members over changes to shift patterns and the loss of overtime pay.
The civilian staff call handlers at the centre, in Netley near Southampton, receive all Hampshire and Isle of Wight 999 calls.
Hampshire police said the revised shift pattern was in the interests of staff.
The union said the changes were being forced through despite a recent internal report which concluded the changes could "result in a loss of morale and additionally a loss of officers and call management staff".
They added that during the last 20 years numbers of control room staff "have increased by only 5%, yet the number of calls answered has increased by more than 2,000%".
But Hampshire police said it was introducing a revised shift pattern, in line with the majority of police officers and staff in operational roles, to enable it to deliver a better, more joined up service.
Meanwhile, a report published by the National Policing Improvement Agency (NPIA) on Wednesday said police forces should develop new self-service systems for victims to report crimes.
The NPIA study urged chief constables to introduce automated systems - on the phone and the internet - to take pressure off police control rooms.