Laurence Harvey

Character: Dr. Francis Trevelyan

Daliah Lavi

Character: Princess Natasha Romanova

Lionel Jeffries

Character: Stanley Farquhar

Eric Sykes

Character: Wrigley

Eric Portman

Character: British Ambassador

Denholm Elliott

Character: Pond-Jones

Wanda Ventham

Character: Mrs. Winters

Marianne Stone

Character: Mrs. Whitby

June Whitfield

Character: Elsie Farquhar

Colin Blakely

Character: Russian Prime Minister

Robert Flemyng

Character: M.I.5 Director

Bernard Archard

Character: Russian Intelligence Chief

Paul Ford

Character: American General

Michael Trubshawe

Character: Braithwaite

Amy Dalby

Character: Miss Marchbanks

John Forbes-Robertson

Character: M.I.5 Workshop Director

R.S.M. Brittain

Character: Commissionaire

Peter Bayliss

Character: Professor

Barry Cryer

Character: Harold Wilson (voice)

Renée Houston

Character: Lady Blanchflower