A police radio mast has joined the ranks of the country's historic buildings.

The 150ft concrete tower at the headquarters of the County Durham force has been given Grade II Listed Building status.

It is one of seven post-war communications structures, including the BT (formerly Post Office) Tower in London to be designated because they represent the "white heat of technology'' promoted by 1960s Labour Prime Minister Harold Wilson.

Ironically, the mast's days could have been numbered because of the introduction of the Airwave digital microwave radio system being adopted by forces across the country.

But because it is listed, it cannot be demolished and now the force plans to continue using it when the new network comes on line later in the year.

The tower, in the HQ's grounds in the picturesque Aykley Heads area of Durham City, was designed and built in the 1960s by Ove Arup and Partners.

A spokesman for the Department of Culture Media and Sport said: "The elegant, ultra-thin design for the county police communication responds to its aesthetically sensitive site overlooking Durham Cathedral."

A Durham Police spokesman said: "There is no denying it is a striking piece of work.''

Other listed structures include the TV broadcasting tower at Emley Moor, West Yorkshire.