Merseyside Police will have to be completely "re-engineered" to save £66m by 2015, its chief constable has said.
Chief Constable Jon Murphy and his senior officers have found savings worth £4.1m in this year's budget and a further £18m in next year's.
"The next phase is to look at core police services - neighbourhood policing, investigations and intelligence processes," he said.
"It's not salami slicing but re-engineering the whole organisation."
He said he could not say how those changes would take shape, except that all aspects of the way the force operated would be considered.
Government funding for police forces will be cut by 20% by 2014-15.
But Merseyside Police is hit harder by that reduction than most other forces, Mr Murphy said.
The area relies on the government for 86% of its funding. The remaining 14% comes from the council tax precept.
This compares to Surrey - which raises 51% of its budget through the precept and relies on the government for just 49% of its funding.
Mr Murphy said he was anticipating having to make cuts when he took charge of the force a year ago this month, but the depth of those cuts was far beyond his worst fears.
Mr Murphy, who grew up on Merseyside and joined his local force as a cadet, said senior officers started looking at how they could make 5% of cuts and then 10%.
"I said look at 15% and everyone thought I was mad," he said.
"Here we are now and it's 20%. They are the deepest in a generation."
Next year's savings have been found by cutting staff, reducing IT support, reducing its dog unit, ending the anti-social behaviour task force and scrapping plans for new police stations.
'More to do'
Senior officers have now been tasked with finding savings for the three years after that, so they can work with a budget in 2015 that is smaller than that for 2005.
Mr Murphy said policing demands have changed dramatically over the past decade.
"We hadn't had the London bombings then," he said.
"We have lots more to do with a lot less resource."
As most of his budget - 86% - is spent on wages, upward of 800 police officer jobs and 1,000 civilian staff will have to be cut.
"It is difficult, it is unpleasant and it is distasteful because we don't want to do it," Mr Murphy said.
"But we could sell all our police stations, cars, radios, and we would still need to lose people from the organisation."
'Bear their share'
Mr Murphy said he anticipated crime rising as public sector jobs are cut and services are stripped back, furthering levels of deprivation.
"It is phenomenally frustrating. It makes you want to weep frankly when you look at the success we have had.
"Just when you start to see real success the rug gets pulled under you."
A spokeswoman for the Home Office said: "The home secretary has been clear the police service will have to bear its share of the cuts.
"We are cutting red tape and bureaucracy, freeing officers to get back to the frontline and focus on cutting crime.
"Police and Crime Commissioners will ensure that police forces are responding to the real concerns of the public by setting priorities and making forces truly accountable to the community."