Margaret Rutherford
Grand Duchess Gloriana XIII
Ron Moody
Prime Minister Rupert Mountjoy
Bernard Cribbins
Vincent Mountjoy
David Kossoff
Professor Kokintz
Terry-Thomas
Maurice Spender
John Le Mesurier
British Delegate
John Phillips
Bracewell - U.S. Delegate
Michael Trubshawe
British Aide
Peter Sallis
Russian Delegate
Graham Stark
Standard Bearer
Mario Fabrizi
Mario - the Valet
Archie Duncan
U.S.A.F. General
Guy Deghy
Russian Scientist
Richard Marner
Russian Air Force General
Allan Cuthbertson
Member of Whitehall Conference
Robin Bailey
Member of Whitehall Conference
Gerald Andersen
Member of Whitehall Conference
Gordon Phillott
Civil Sergeant
George Chisholm
Wine Waiter
Frank Duncan
News Announcer
Ed Bishop
American Astronaut
Bill Edwards
American Astronaut
Laurence Herder
Russian Astronaut
Harvey Hall
Russian Astronaut
Stringer Davis
1st Councillor (uncredited)
Lucy Griffiths
Lady-in-Waiting (uncredited)