Private security firm G4S has been contracted to design, build and run a police station in Lincolnshire, in what is thought to be one of the most radical outsourcing deals seen so far in Britain.

Under the £200m 10-year deal signed on Wednesday, more than 540 civilian police staff will join the company, which will deliver a range of middle and back-office services.

This means that almost half the force's 900 civilian workers will be transferred to G4S as a result of the deal.

The new police station, based on a hub-and-spoke design, with 30 custody cells and a two-storey office block will house up to 120 operational staff. The police officers involved will remain police force employees.

G4S will provide Lincolnshire police with a range of support services, including running cells, administering drug tests, firearms licensing, human resources, computer systems and managing the force's vehicle fleet.

It will also establish a shared services centre that will enable it to sell its expertise in human resources, payroll and finance to other forces.

Lincolnshire police authority is facing a £19.7m cut in its funding from Whitehall over the next four years. G4S claims savings of £28m over the next 10 years or £2.8m a year will be made as a result of the deal.

The Lincolnshire police authority chairman, Barry Young, said: "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.

"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."

Kim Challis, group managing director of G4S government and outsourcing, said the deal was the first of its kind in Britain.

"We are 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," he said.

"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."

But the Police Federation has raised concerns about the deal pointing out that police force staff have an enshrined sense of public duty, whereas private employees may not.

"Our concern is the resilience of the companies doing this," said Simon Reed, the organisation's vice-chairman. "When we have national emergencies or unforeseen events, will they be able to bring their staff in to work long hours, regardless of what their contracts say?"