Humberside Police could axe 850 jobs to save £30m
Humberside Police could lose a third of its workforce as it faces making cuts of up to £30m in its budget, the Police Federation confirmed.
Up to 250 officer posts and 600 civilian jobs are expected to be slashed by 2018.
Union Unison said the cuts would have "a massive impact on the community".
The force said it was looking at how to make the savings but admitted "it will inevitably lead to a smaller organisation".
Police Federation chairman John Blanchard said the force had "already been faced with harsh losses" as the number of employees dropped from about 2,200 to 1,700 staff over the last five years.
"It's potentially a huge loss," said Mr Blanchard.
"The fact is with those kind of numbers you are not going to be able to serve the community the way we should be doing.
"Civilian staff are frontline staff - they include PCSOs, they are the ones who provide the foot patrol, give a visible presence and provide that constant reassurance to the community."
Tony Green, assistant branch secretary for the staff union Unison, said he was aware of the proposals and was "very concerned".
"We don't believe you can make that many cuts of police staff without severely affecting the service given to the public.
"It would have a massive impact on the force and community."
He said the work done by frontline staff - including PCSOs, control room and 999 call handlers - was invaluable.
"Without them the police officers cannot function," added Mr Green.
In a joint statement, Chief Constable Justine Curran and Humberside Police Crime Commissioner Matthew Grove said work was on going to "identify options" on how to make the savings but could not provide further details.
"We are involving staff from all parts of the organisation in this work and recognise that it will inevitably lead to a smaller organisation."