Prince Harry will set his sights on dad Charles and Camilla and deepen the rift with brother William in his new memoir, a royal author claims.
Ex-Vanity Fair editor Tina Brown, said the Duke of Sussex "can't stand" his father's second wife and doesn't want her to be Queen.
She added he will "go after" the royal couple in the explosive book, and claimed that his relationship with William is "very bad".
If true, the rift already present between Harry, 37, and wife Meghan Markle, 40, and the rest of the Firm could be further deepened.
Harry, who lives with Meghan and their two children in California, is understood to have received a £15million advance on the book, due out later this year.
Neither of the Sussexes were present at the memorial service for Prince Philip this month.
The Queen was said to have been upset that her grandson rejected an invite but could not persuade him to change his mind.
Harry is in the middle of a dispute with the Home Office after it refused to allow him access to Met Police security on the scale of working members of the Royal Family.
Having stepped down in March 2020 and moved abroad, the prince is willing to pay for such a service for his family whenever they visit Britain.
But said he feels without it there would be a major security risk.
The book could prove a major cash cow for the Sussexes but comes at a risk.
He and Meghan had already added to tensions following them stepping down from their duties by taking part in a series of televised interviews in which they spoke about their royal lives.
In particular, the controversial Oprah Winfrey chat, just prior to the Duke of Edinburgh's death last spring in which Meghan claimed an unnamed senior royal had made racially insensitive remarks about then-unborn son Archie.
She also accused Kate of making her cry during the preparations for her wedding.
Referring to the upcoming book, Ms Brown told the Sun : “Harry’s not going to go after The Queen, she’s sacrosanct. And he probably won’t go after Kate, who he’s very fond of.
"But he will go after Charles and Camilla and maybe William.”
Ms Brown also told the Telegraph Magazine on Saturday, that Prince William - whose relationship with Harry has long been fractured - was "disgusted about Meghan’s attack on Kate because she can’t answer back".
“But that’s nothing compared to how furious he’s going to be when this book comes out,” she added.
Ms Brown is due to release her own book, The Palace Papers: Inside the House of Windsor, next week.
