The majority of the electorate lived in former mining or steel towns, where Labour traditionally have polled higher than other parties, with the remainder being in rural farms and villages throughout valleys cleft from the eastern, rocky part of the Pennines.

As a result of the periodic review of parliamentary constituencies following the re-organisation of local government under the Local Government Act 1972, the seat underwent a major redistribution for the 1983 general election: the town of Consett was regained from the abolished constituency thereof, and Brandon and Spennymoor were transferred to City of Durham and Sedgefield respectively.

[5] (NB Boundary Commission proposed name was "Lanchester") Spennymoor transferred from Durham with the parish of Brancepeth.

The 1997 boundaries were retained despite the official description of the constituency changing slightly in terms of the names of the local authority wards.

In 2016 the incumbent MP, Pat Glass, announced her intention to step down at the 2017 general election in the wake of the Brexit referendum.