An upcoming BBC drama about the royal family has been branded as “distasteful” for a portrayal that “denigrates and undermines” the monarchy.

King Charles III, set around the future of Buckingham Palace, depicts an increasingly delusional royal family and their bitter personal rivalries during Prince Charles’ accession to the throne after the Queen’s death.

But its controversial scenes, including the funeral of the Queen, a scheming Princess Kate, and the ghost of Princess Diana has caused major uproar among Britain’s politicians.

“It’s unfortunate the BBC would seek to promote this flight of fantasy, which many licence-fee payers will find distasteful and I believe denigrates and undermines our royal family,” Tory MP Andrew Brigden said.

“I hope that the BBC will make clear that the production is pure fiction.”

The 90-minute drama, adapted from a play of the same name, begins with an image of the coffin of Queen Elizabeth.

It charts the progress of the new King Charles – played by the late Tim Pigott-Smith, who died suddenly on April 7 – as he seeks political control.

When Charles refuses to sign a bill restricting a free press, he provokes a constitutional crisis and rioting on the streets ensues.

In one scene, the ghost of Princess Diana tells her son William he will be “the greatest king of all”, while another plot shows Camilla slapping the king-to-be when tensions boil over.

The fictional portrayal also uses real-life scenarios, showing Prince Harry struggling with issues surrounding privacy with his girlfriend – echoing his statement condemning intrusion into his relationship with American actress Meghan Markle last year.

However, in King Charles III, Harry is dating a British Republican named Jess Edwards, who is at the centre of a sex scandal in the media.

Meanwhile, a vindictive Duchess of Cambridge, played by Peaky Blinders’  Charlotte Riley, is portrayed as a scheming Lady Macbeth-like figure, who will stop at nothing to usurp Charles in favour of her husband, William.

The drama ends with Charles’ abdication and the coronation of William, with Kate as his queen.

Watch the King Charles III trailer below:

Sir Gerald Howarth, a former defence minister and outgoing Tory MP, labelled the BBC program “extraordinarily insensitive”.

“We have a sovereign who commands universal respect across the nation and the rest of the world,” Sir Gerald told The Telegraph.

“It is extraordinarily insensitive for an organisation which is so consumed with political correctness.

“It is pure indulgence by the BBC to run a play featuring the demise of the Sovereign and ascribing to a popular member of the royal member [the Duchess of Cambridge] base motives.”

Director Rupert Goold attempted to soften the outrage, saying the show contained issues of the “greatest sensitivity”, with some scenes altered from the original stage version.

However, even “certain actors” found the production too controversial, refusing to be involved over fears it might jeopardise a future knight or damehood.

“Even with the stage version, we’d been through long conversations with lawyers and certain actors refusing to be involved because of how it might affect their future relationship with the honours system,” Mr Goold told Radio Times magazine.

King Charles III will premiere on the BBC in the UK on May 10.