King Charles III: Outcry 'surprises' Prince William actor Oliver Chris

The programme suggests what might become of the royal family after the Queen is gone

The actor who plays Prince William in a new BBC drama has said he's "surprised" by the controversy it has caused.

BBC Two's King Charles III, which will be shown on Wednesday, imagines events after the death of the Queen.

It has ruffled feathers for raising the question of Prince Harry's paternity and showing Princess Diana as a ghost.

Oliver Chris, who plays William, told BBC Breakfast people may find the Diana scenes "difficult to watch" but that they are handled "very sensitively".

King Charles III has been adapted from the award-winning play of the same name by Mike Bartlett.

This week, the Mail on Sunday ran a front page story voicing concerns from Diana's friend Rosa Monckton that the Prince Harry paternity suggestion was "deliberately causing pain to a real living person in a salacious fashion".

The new King Charles III is seen at the centre of a constitutional crisis

Speaking to BBC Breakfast on Tuesday, Chris said he had found the controversy "really surprising".

Asked whether showing the ghost of Diana was insensitive, he replied that one of the themes of the programme was to depict the "friction" between the lives of the real people in the royal family and their institutional roles.

"We can only, as the subjects, imagine what that might be like, which is exactly what this does," he said.

"And I think it would be strange if Diana was not a part of the story because she's such a big part of the princes' and Charles' psychology.

Tim Pigott-Smith played Charles III on stage as well as on screen

"I understand how people might find that difficult to watch. I personally felt that what we see in King Charles III is this really extraordinary, intelligent addition to the debate about our monarchy, and I feel that the presence of Diana is done very sensitively.

"I think it's quite a tasteful addition to this controversial, provocative, thought-provoking story."

He described the drama as "quite a pro-monarchist film because it upholds the pillars of our society".

Piggott-Smith death 'a shock'

He said: "I would like to think that certainly if William saw my portrayal he would see that it's done with an awful lot of respect and admiration."

Chris also paid tribute to his co-star Tim Pigott-Smith, who plays King Charles and who died last month.

"He was a great friend and a real mentor. For him to be taken from us before he even got to see the film - it's one of those cruel jokes in life. I still can't accept it. It's so recent and such a shock.

"As a final testament to his abilities I think he gives a most extraordinary detailed, nuanced and beautiful performance of this man that we all know and think we know, and maybe love or don't love."