Prince Harry's book "was horrible," according to historian Simon Heffer, who warned the duke has since "lost his credibility."
The Duke of Sussex caused a stir when he released his memoir, Spare, last year that included a series of attacks on senior members of the Royal Family.
Asked whether he had read the book, Heffer said: "I read bits of it. I mean, life's too short, but I read enough of it to get a flavour of it. I thought it was horrible."
GB News host Steven Edginton asked: "Do you think that we should accept him back to the UK if Hollywood don't want him?"
He responded: "It's not up to us. The decision has to be made by his father and with the advice of his brother.
"I think if things go wrong for him there, and he's willing to come back and play by the rules that the rest of the Royal Family play then it would be wrong of any of us as mere subjects, to say we shouldn't come back.
"But there's no doubt that if he continues to embarrass the Royal Family and to make a bit of an exhibition of himself, the public won't like it, and he will be a drag on the Royal Family."
