The show stars Reg Varney as bus driver Stan Butler, Bob Grant as his conductor and best friend Jack Harper and Stephen Lewis as their inspector Blakey. Anna Karen plays Stan's sister Olive Rudge and Michael Robbins plays her husband Arthur Rudge. The role of Stan's widowed mother Mabel Butler was played by Cicely Courtneidge in series 1 and by Doris Hare in the other series. 