Prince Charles said he is not "so stupid" and knows that at the time he becomes king he can not interfere with England's policy.
The British monarch tried to distract fears of his activism in topics from global warming to preserving architecture in the BBC documentary of his 70s.
"I'm not that stupid," Charles said when he asked if his political campaign would continue after he succeeded his queen, Queen Elizabeth II. "I know that being a king is a separate exercise, so I fully understand how it works."
The Prince has raised fears in the past by expressing his commitment to organic farming, traditional architecture and environmental causes. But Charles defended his past actions when he said he had always kept himself away from partisan politics.