King Charles could strip Prince Harry and Meghan Markle of their titles in retaliation for "going fully rogue" with a tell-all memoir, a royal biographer has claimed.
Author Tom Bower also warned the new monarch could withhold Archie and Lilibet's titles over the 416-page book called Spare, which he believes is "make or break" for the Sussexes.
The memoir was set to come out this autumn but the date was pushed back to January 10 as a mark of respect following the death of the Queen.
Harry has vowed it will be a "truthful and wholly accurate" account of his life - with the announcement of the novel reportedly sending a "tsunami of fear" through royal circles.
Publishers Penguin Random House described the memoir as an “honest and captivating personal portrait” of his “lifetime in the public eye from childhood to the present day”.
Mr Bower told The Sun : "This book is really make or break. I imagine that King Charles has been warned that any retaliation won't be pretty.
"All that King Charles can really do is to withhold the titles for his grandchildren Archie and Lilibet.
"Ultimately, I suppose, he could take away Harry and Meghan's titles as well, but that's pretty drastic.
"I don't know what else he can do. If it is as bad as I think it is, then Harry and Meghan have gone fully rogue."
It will cost £28 for a hardback copy, with the audio book - voiced by Harry himself - priced at £20, but is already being offered at half the cost by Waterstones.
The publisher said that Harry had donated £1.3m of his £18.4m advance to his children’s charity Sentebale, as well as giving £300,000 to WellChild, a charity for disabled children of which he is patron.
The latest comments come as separate reports suggest that King Charles has "no desire" to heap humiliation on Prince Harry by stripping him of his royal role of Counsellor of State, according to an expert.
It has emerged that Charles will instead expand his pool of advisors and for the first time take on more than five Counsellors of State to assist him in official business, should he be out of the country or become unwell to carry out his duties.
The positions are currently held by Prince William, Andrew, Harry and Princess Beatrice, chosen because they are the four next in line to the throne and are at least over the age of 18. Queen Consort Camilla is also a Counsellor of State.
It was widely thought the King would strip his Harry and Andrew of the roles as they are no longer working members of the royal family.
But royal sources have now confirmed the King will not allow them to be stripped of the role - and instead open it up to Princess Anne, Prince Edward and the Princess of Wales.
Ingrid Seward told the Mirror: "King Charles has no desire to heap humiliation on the sensitive shoulders of his younger son the Duke of Sussex or indeed his brother the beleaguered Duke of York.
"Both are counsellors of state which means that when the king is out of the country, they have the power to act on his behalf alongside another counsellor.
"The question arose when the Queen was still alive and it was decided that instead of removing the Dukes of Sussex and York as they were no longer working royals, it would be easier to simply appoint more counsellors of state to ensure Harry and Andrew were never called upon to perform the duties."
