Northamptonshire County Council said the building in Angel Street would replace 12 buildings it could “no longer afford”.

The project is out to tender with the council aiming to appoint a contractor by the end of August.

The Northampton town centre office block is designed to house 2,000 county council workers and will be built on a council car park in Angel Street, at the back of the current County Hall building.

The new building, codenamed Project Angel, is expected to save up to £54m in the future running costs.