George Cole

Character: George Archibald Potts

Oskar Homolka

Character: Zekov

Nadia Gray

Character: Tania

Wilfrid Hyde-White

Character: Sir Hubert Wells

Richard Wattis

Character: Barnes

Irene Handl

Character: Mrs. Tidmarsh

Christopher Lee

Character: Russian Agent (uncredited)

Frederick Leister

Character: Prime Minister

Frederick Valk

Character: Rakov

Geoffrey Sumner

Character: Pike

Ronald Adam

Character: Barworth Controller

Edwin Styles

Character: Barworth Superintendent

Kynaston Reeves

Character: Barworth Director

Ernest Jay

Character: Professor Layton

Michael Medwin

Character: Smedley

Henry Hewitt

Character: Minister of Health

Walter Horsbrugh

Character: 1st Cabinet Minister

Anthony Shaw

Character: 2nd Cabinet Minister

Tim Turner

Character: 1st Reporter

Gibb McLaughlin

Character: Schoolmaster

Michael Balfour

Character: Jersey Sailor

Hal Osmond

Character: Jersey Waiter

Charles Goldner

Character: Gaston

Ronnie Stevens

Character: Aubrey

Eleanor Summerfield

Character: Cecilia

Phyllis Morris

Character: Mrs. Tweedy

Myrtle Reed

Character: Jersey Air Hostess

Ina De La Haye

Character: Madame

David Hurst

Character: Deutsch

Bernard Rebel

Character: Trubiev

Olaf Pooley

Character: Roblettski

Guido Lorraine

Character: 1st M.V.D.

Terence Alexander

Character: 2nd M.V.D.

Richard Marner

Character: Russian Sentry

Martin Boddey

Character: Russian Security Officer

Gerard Heinz

Character: Russian Director of Plant

Fred Berger

Character: Russian Doctor

Victor Maddern

Character: British N.C.O.

Reed De Rouen

Character: 1st U.S. Soldier

Johnny Catcher

Character: 2nd U.S. Soldier

Willoughby Gray

Character: British Officer

Anton Diffring

Character: Border Police GDR (uncredited)