 Rotherham Corporation has been running trolleybuses since 1912, but were reluctant to allow Mexborough and Swinton vehicles into the town.However, the two sides reached an agreement in 1926, under which Rotherham would convert its section of tramway ready for trolleybus operation and allow Mexborough trolleybuses to reach the town centre, while Rotherham vehicles could run over Mexborough's routes to various termini.The necessary powers were granted by an Act of Parliament obtained in 1927, which also allowed them to extend the system.