The Home Office is set to move to a £311 million radical steel and glass complex.

Whitehall mandarins will eventually move to 2 Marsham Street on the site of the former offices of the Department of the Environment. The three tower blocks currently on the site will be demolished as soon as possible.

The offices will be financed by a public private partnership deal that will last for around 29 years.

Home secretary David Blunkett revealed in a written answer on Wednesday that he has signed a contract with Annes Gate Property (AGP) for the complex which will contain both the Home Office and the Prison Service.

The deal, which has taken almost six years to conclude, will leave free Home Office's current base at the Basil Spence-designed tower in Queen Anne's Gate for the Lord Chancellor's department to take over.

The new seven-storey glass and steel construction will include bullet and bomb-proof glass and will be built by the French construction firm Bouygues. It will also contain some affordable housing and retail development.

It will comprise of three linked buildings and the lower ground floor, which will benefit from natural light will include a restaurant, library and sport and recreation facilities.

The building, designed by leading British architect Sir Terry Farrell, will be finished by Spring 2005.

Farrell is enjoying a renaissance in the UK and is seen as one of the leading lights in building design alongside Sir Richard Rogers, Lord Foster and Nicholas Grimshaw.

Major designs have included Kowloon station in Hong Kong, New Seoul airport, the new Charing Cross station and The Deep aquarium in Hull which opened to critical acclaim last week.

He hit the headlines last year for creating a radical makeover of Buckingham Palace which involved tearing down the front façade and gates.

Farrell also came out in support of Prince Charles' views on architecture which are anti-modernist.

He is no stranger to working with high security government buildings; he designed MI6's headquarters at Vauxhall Cross, London which was immortalised in the James Bond film Tomorrow Never Dies.

Farrell did not have to work hard to improve the current crumbling concrete towers which were are know as either "the three ugly sisters" or the "Marsham Street toast rack".

Beneath the current building is part of Whitehall's nuclear bunker complex built for the Cold War where senior government officials would have been evacuated in the event of a Soviet attack.

John Gieve, permanent secretary at the Home Office, said the building would offer a long-term solution to the department's long-term accommodation needs.

"Modern office accommodation will help us do our business better. In partnership with the private sector, the project to create new offices at Marsham Street will give much better value for money than any of the alternatives open to us. With the early demolition of the present Marsham Street tower blocks, the project will also remove a blot on the London landscape," he said.