These units were built to operate commuter services on the Great Eastern Main Line (GEML) from London Liverpool Street to Shenfield, Witham, Colchester, Walton-on-the-Naze and Clacton.

The braking system is basically the same as the Class 302 stock with the exception of the motor coach retaining the 16 in (406.4 mm) cylinder rather than the 12 in (304.8 mm) as fitted to Class 302 after replacing the cast-iron brake blocks with composite (Ferodo) type.

Individual carriages were numbered as follows: A second batch of nine units, numbered 313–321, were built for boat train services on the London, Tilbury and Southend line in 1959–60, from London Fenchurch Street to Tilbury Riverside.

Each unit was formed of four carriages: two outer driving trailers, an intermediate trailer, and a motor luggage van, with the reduction in luggage some MLV's were converted at Swindon Works with a different seating arrangement to the original passenger vehicles.

Individual carriages were numbered as follows: When Tilbury Docks closed as a cruise liner terminal, these units were made redundant and withdrawn from service in 1983.

Finally, a third batch of 3-car units were built in 1961 for suburban services from London Liverpool Street to Chingford and Enfield Town.

Each unit was formed of three carriages: two outer driving trailers, and an intermediate motor coach.

314/319/321) were converted into Class 308/4 postal units by the Parcels sector, with the removal of the intermediate trailer, and renumbered 308991–993.

In 1996, with the privatisation of British Rail, the Class 308 fleet passed into the ownership of Angel Trains and were leased to the Regional Railways North East franchise.

The carriage has been stripped of asbestos, and the full internal rebuild was abandoned in favour of housing the salvaged parts of the London Underground Victoria Line Cobourg Street signalling centre, and much of the former Brixton interlocking machine room equipment.