The actor landed a Best Actor Academy Award nomination for his portrayal of intelligence officer George Smiley in the espionage thriller, and reveals he's open to bringing the character back to the big screen for an adaptation of another one of author John le Carre's novels.
He tells Britain's The Sun on Sunday, "They are talking about doing Smiley's People, which is the third book in the trilogy, with the same people."
But while he loves the role, Oldman admits he'd make a lousy spy.
He adds, "I would be terrible. I know they play roles and take on other identities, but acting is sort of the opposite of it. You're not lying. You're trying to be kind of honest. Dishonesty and infidelity and all of that - I can't stand it. It's not a part of my make-up."