 The 1971 Local Government White Paper proposed abolishing county boroughs , which would have left Plymouth , a town of 250 @,@ 000 people , being administered from a council based at the smaller Exeter , on the other side of the county . This led to Plymouth lobbying for the creation of a Tamarside county , to include Plymouth , Torpoint , Saltash , and the rural hinterland . The campaign was not successful , and Plymouth ceased to be a county borough on 1 April 1974 with responsibility for education , social services , highways and libraries transferred to Devon County Council . All powers returned when the city become a unitary authority on 1 April 1998 under recommendations of the Banham Commission . 
