Page "British Rail Class 300" Paragraph 2

However, the age and design of the units counted against them, and the decision was taken instead to build new units, which became the Class 325.

However, the driving cars from the Class 307s were still used by the Parcels sector.

They were converted into Propelling Control Vehicles ( PCV ) and used as a kind of driving trailer car at the end of locomotive-hauled parcels trains.