Hugh Sinclair
— Humphrey Mansfield
Griffith Jones
— James Brodie
Francis L. Sullivan
— Leon Poiccard
Frank Lawton
— James Terry
Anna Lee
— Ann Lodge
Alan Napier
— Sir Hamar Ryman M.P.
Basil Sydney
— Frank Snell
Lydia Sherwood
— Myra Hastings
Edward Chapman
— B.J. Burrell
Athole Stewart
— Police Commissioner
George Merritt
— Inspector Falmouth
Garry Marsh
— Bill Grant
Ellaline Terriss
— Lady Willoughby
Roland Pertwee
— Mr Hastings
Eliot Makeham
— Simmons
Frederick Piper
— Pickpocket (uncredited)
Henrietta Watson
— Mrs. Truscott
Jon Pertwee
— Rally campaigner (uncredited)
Liam Gaffney
— Taxi driver (uncredited)
Manning Whiley
— (uncredited)
Neal Arden
— (uncredited)
Basil Radford
— (uncredited)
Edward Rigby
— (uncredited)
Paul Sheridan
— (uncredited)
Winston Churchill
— Self (archive footage) (uncredited)
Arthur Hambling
— Constable Benham
Bryan Herbert
— Taxi driver (uncredited)
Adolf Hitler
— Self (archive footage) (uncredited)
James Knight
— Policeman Outside Parliament (uncredited)
Percy Parsons
— American Broadcaster (uncredited)