A private security firm has signed a contract to build, design and help run a police station.
G4S has signed the deal, thought to be the first of its kind, with Lincolnshire Police Authority in a move which could save the force £28 million, the firm said.
It comes amid concerns from the Police Federation that public sector staff could have a sense of duty which the private sector may not.
The police station, based on a hub-and-spoke design with 30 custody cells, will also be extendable in the event of major incidents or anticipated peaks in arrests and is expected to account for a "major proportion" of the savings, G4S said.
The station will also house up to 120 operational police staff and cut running costs by saving £5 million over the next 10 years.
From April 1, and for at least the next 10 years, G4S Policing Support Services will also provide Lincolnshire Police with administrative and operational services including human resources, IT, fleet management, custody services and firearms licensing.
A so-called "shared services centre" in Lincolnshire will effectively enable the force to sell on these services to other forces, G4S said.
Kim Challis, group managing director of G4S Government and Outsourcing Services, said: "G4S is excited to be partnering with Lincolnshire Police in delivering this landmark programme, which is the first of its kind in the UK.
"Lincolnshire is leading the way in responding to the challenges of today's economic environment and this transformation project will mean many of the services provided by the police will now be delivered externally by specialists who can deliver greater savings and improve efficiency.
"We are particularly delighted to have the opportunity to implement many new innovations, such as our purpose-built Bridewell custody suites - the first of which will be completed within a year.
"This new police station will be the first, tangible demonstration of the benefits this partnership will bring to Lincolnshire.
"But others, such as the planned shared services centre, will place Lincolnshire at the heart of Britain's policing future, generating vital additional income as well as creating new jobs.
"This is an exciting time for Lincolnshire and we are proud to be part of it."
Barry Young, chairman of Lincolnshire Police Authority, said: "G4S shares our values and our ambition to maintain and improve services.
"It has the skills and the experience to help make a real difference to the way in which Lincolnshire is policed.
"By taking over a range of support functions, G4S will contribute to the force's aim of being able to put 97% of its warranted officers in frontline roles by April."
He went on: "Crucially, the new strategic partnership will also deliver significant infrastructure investment that will offset the budget reductions called for by the Government.
"I believe we are leading the way. We have demonstrated that it is possible to negotiate a complex agreement in a relatively short period of time that will provide benefits well into the future."
Simon Reed, vice-chairman of the Police Federation which represents rank-and-file officers in England and Wales, said: "There are many examples of private companies supporting and providing services to the police service.
"In order to guarantee the maximum resilience of the police service we need assurances that police staff are available to support officers especially when they are working long hours and under extreme pressure during major incidents.
"Our primary concern is the impact future private contracts will have on the flexibility of the police service. We would hope that officers are not left high and dry in times of national emergency.
"Police officers should not have to worry about inheriting additional workloads as a result of cuts or changes to the working conditions of support staff."
Unison warned it was a "dangerous experiment" that had not been proven to work in the police service.
Ben Priestly, the union's national officer, said: "This is far more than just taking over a police station - it will involve running the majority of police support services in Lincolnshire.
"We've yet to see a real business case, and past experience shows that savings are often over-promised and under-delivered."
He went on: "Public accountability will also take a hit. If local people have complaints about the service, they'll no longer be able to go to the Independent Police Complaints Commission.
"Taxpayers' money will end up lining shareholders' pockets when they should be going towards giving the public better services.
"The coalition's cuts mean that other police authorities may be tempted to privatise services to deliver savings, but we would call on them not to do so.
"Bringing the private sector in is a dangerous experiment, and there's no proof that it will work for police services."