The Royal Family has "very real fears" that Prince Harry's upcoming memoir could destabilise the monarchy by undermining the reputation of Prince Charles when he ascends the throne.
The Duke of Sussex "blindsided" senior royals on Tuesday with the revelation he will release an "intimate and heartbreaking" biography next year which will supposedly cover his entire life, including the scandalous Megxit events of last year.
He said he was not writing the book "as the prince I was born as, but as the man I have become".
"I've worn many hats over the years, both literally and figuratively, and my hope is that in telling my story - the highs and lows, the mistakes, the lessons learned - I can help show that no matter where we come from, we have more in common than we think."
The announcement, which insiders are describing as "deeply disrespectful" and the "last straw" for relations between Harry and the rest of his family, has already prompted calls for the Duke and Duchess of Sussex to be excluded from the Queen's Platinum Jubilee celebrations next year.
The book will coincide with the Queen's platinum jubilee and there are worries from inside the family that it will overshadow celebrations of her 70 years on the throne.
A source told the Daily Mail there is also "anger and disappointment" among those who work for the Royal Family that the Queen has anxiety over the book's content, especially just months after the Duke of Edinburgh's death.
There were rumours Harry was releasing four books as part of his deal, including one after the Queen dies and another wellness book by his wife Meghan. But lawyers for the couple said this is "false and defamatory".
"Contrary to false media reports, there is only one memoir planned by The Duke of Sussex and it's scheduled to be published in late 2022 as was announced earlier this week by Penguin Random House," a spokesperson for Harry said.
Harry's deal is reportedly worth £18 million (NZ$35.4 million) and he is set to donate all proceeds to charity.
Brits are also displeased with the Duke's book deal, with a recent survey by British pollster YouGov finding 38 percent believe it's "very inappropriate" for him to publish a memoir, while a further 15 percent say it's "fairly inappropriate". Of the 5808 people surveyed, 14 percent called it "fairly appropriate" and 9 percent said it was "very appropriate". The rest didn't know.
They're also not that interested in reading Harry's account. Just 14 percent of those questioned are either "very" or "fairly" interested in reading the book, while 67 percent are "not interested at all" and 15 percent are "not very interested". The rest didn't know.