Meghan Markle's former friend said the King "must intervene to stop the Royal Family becoming a laughing stock".
Lizzie Cundy, a TV personality, has hit out at her former friend the Duchess of Sussex following an episode of Family Guy that brutally mocked Prince Harry and Meghan.
The US comedy included a scene which focused on the Duke and Duchess of Sussex.
The character Peter Griffin explained he would "go it alone" similar to the Sussexes having suffered financial issues.
Lizzie Cundy is an ex-pal of Meghan Markle's
PA
The show then cut to a scene depicting Meghan and Harry sitting around a large swimming pool.
Viewers then saw Harry saying he "shouldn't have left the made-up nonsense," referring to the Royal Family.
Cundy, who previously claimed she was "ghosted" by the duchess, believes that if Meghan releases a memoir, it would lead to the couple becoming a "laughing stock".
Meghan and Cundy became friends in 2013 at the Global Gift Gala when the former Suits actress was trying to crack the UK showbiz scene.
King Charles and Meghan Markle at her wedding in 2018
PA
But following her relationship with Prince Harry becoming public, Meghan cut all contact with Cundy.
The model said: "In light of the recent cartoons mocking Meghan and Harry, King Charles needs to intervene and stop her memoirs.
"Enough now of their moaning and whinging, all they do is backstab and make a career out of complaining.
"It's so bad now that we're a laughing stock across the pond making cartoon features of the couple – it's time for this to stop."
Meghan and Harry depicted in Family Guy
FOX
The star also told The Mirror: "Meghan can forget a career in politics because, with their moaning, they've become laughingstocks, not just here but in the States.
"Their celebrity friends have moved away from them.
"They've had to try and reinvent themselves but they don't know how.
"They make money by slating our Royal Family."
LATEST ROYAL NEWS:
WATCH NOW: Family Guy mocks the Sussexes
Cundy believes King Charles "needs to intervene" to prevent Meghan from sharing her memoirs over fears it could be more explosive than Harry's book, Spare.
She added: "Meghan, put the pen down, the Royal Family can't take it anymore and the British public has had enough.
"The royals can't take another cartoon series of them being mocked.
"Please, for once, put the pen down. King Charles, grow a backbone and tell her straight."