Frontline services provided by North Wales Police are under threat because of a funding crisis, according to the force's chief constable.
Mr Brunstrom claimed funding was 'skewed towards big cities'
Richard Brunstrom told BBC Wales' Dragon's Eye that the Home Office's funding formula favoured urban forces and penalised rural areas.
He said planned cuts were because he "cannot afford" current staff levels.
The Home Office said North Wales Police had received extra funding and services should be protected.
Last month, the force announced 120 backroom posts would be cut by March 2007.
Mr Brunstrom said funding was "increasingly skewed towards big cities".
He said: "They can't skew the money towards big cities and then say there are no consequences for rural areas like north Wales or Lincolnshire."
He said the 120 jobs would go because of a £2m cut in funding this year and an anticipated £3m cut in 2007.
"I simply can't afford the staff that we've got," he said.
Mr Brunstrom said the force had followed UK government strategy but the money had run out.
"I now cannot afford the number of staff that we have been encouraged to employ, so it's very simple - we will have to downsize," he said.
He said the loss of the civilian posts would affect frontline services as officers would "without question" be used to fill the gaps.
Mr Brunstrom faced criticism this month from a group of north Wales Labour MPs.
Mark Tami MP for Alyn and Deeside claimed a "frightening" amount of money had been "wasted on gimmicks" and Ynys Mon MP Albert Owen accused the chief constable of scaremongering over job cuts.
But his position has been defended by Conservative MP for Clwyd West David Jones, who said the Labour MPs were "playing politics with an important public service".
He told BBC News: "If you have a look at North Wales Police's record, they're a pretty efficient force.
"We've got a Home Office which, by the admission of its own Home Secretary is dysfunctional and not fit for purpose.
"Last year we had the catastrophic attempt to merge police forces which wasted about £250,000 of North Wales Police's money.
"It is a crisis of government funding and if the chief constable doesn't stand up for his force and draw attention to the problems that it faces, who can do that?"
The Home Office said North Wales Police had received millions of pounds in extra funding so front-line services and neighbourhood policing should be protected.
The interview with Richard Brunstrom can be seen on Dragon's Eye, on Thursday on BBC2W at 2100 GMT and BBC1 Wales at 2235 GMT.