Prince Charles tells new BBC documentary he will not be as politically involved when he becomes King

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Asked by programme maker John Bridcut if he will continue to speak out when he becomes King, Charles says: “I’m not that stupid, I do realise that it is a separate exercise being sovereign. So of course, you know I understand entirely how that should operate.”

The royal also compares himself to Prince Hal in Shakespeare’s Henry IV and Henry V history plays who abandons his youthful exuberance when he assumes the throne.

“I have tried to make sure whatever I’ve done has been non-party political, and I think it’s vital to remember there’s only room for one sovereign at a time, not two,” he says.

“So, you can’t be the same as the sovereign if you’re the Prince of Wales or the heir. But the idea somehow that I’m going to go on in exactly the same way, if I have to succeed, is complete nonsense because the two… the two situations are completely different. You only have to look at Shakespeare plays, Henry the Fifth or Henry the Fourth part 1 and 2, to see the change that can take place because if you become the sovereign, then you play the role in the way that it is expected.

“So, clearly I… I won’t be able to do the same things I’ve done, you know, as heir, so of course you operate within the… the constitutional parameters. But it’s a different function."

The revealing documentary also includes interviews with Charles' sons William and Harry and features behind the scenes footage of the Prince of Wales on various royal tours – as well as feeding his chickens at his home at Highgrove and collecting their eggs.

His sons use their interviews to paint a picture of Charles as a workaholic – and both of them plead with their father to take it easier.

Harry, Duke of Sussex, says: “He does need to slow down, this is a man who has dinner ridiculously late at night.

“And then goes to his desk later that night and will fall asleep on his notes to the point of where he’ll wake up with a piece of paper stuck to his face.”

William, Duke of Cambridge, adds: “The man never stops. I mean, when we were kids there was bags and bags and bags of work that was… the office just sent to him. We could barely even get to his desk to say goodnight to him."

The Prince of Wales’ sons also reveal that their father’s passion for the environment meant that he made them pick litter when they were younger, and that they were teased at school for it.

“You know we were… we were in Norfolk on school holidays and we went out litter picking with him, and again both of us thought, ‘Oh this is nothing wrong, everyone must do it’, you know, we’re there with our… basically spikes,” said William.

Harry added: “But he’s done an amazing job and without telling us what we should be doing or the direction that we should go in, he’s just let us learn from… from the nature of the job, learn from him, learn from Mummy, to the point where I used to get taken the mickey out of at school for just picking up rubbish.”

Both men say they have also assumed their father's habit of switching off lights.

"I know I’ve got serious OCD on light switches now, which is terrible," says William.

The warm portrait also includes interviews with the Duchess of Cornwall who discloses a hidden talent of the future monarch's – doing the Harry Potter voices.

Speaking of his interaction with his grandchildren, she says: “He will get down on his knees and crawl about with them for hours, you know, making funny noises and laughing and my grandchildren adore him, absolutely adore him. He reads Harry Potter and he can do all the different voices and I think children really appreciate that."

Prince, Son and Heir: Charles at 70 is on BBC1 on Thursday 8 November at 9pm

This article was originally published on 8 November 2018