A friend of the new Queen Consort said Prince Harry and Meghan probably won't be invited to King Charles III's coronation if Harry attacks Camilla in his upcoming book.
The friend told the Daily Beast that King Charles does not want his wife to be ridiculed by his son in the new book.
"It is one thing for Harry to attack Charles, he can take it on the chin, but if Harry forces him to choose, by laying into Camilla in his book, I have no doubt he will choose Camilla."
Prince Harry's tell-all memoir was set to be released by the end of this year, but the launch date is believed to be pushed back because of Queen Elizabeth II's death.
Author of The New Royals Katie Nicholl told the Daily Beast, Charles does want his son and his daughter-in-law at the coronation but expects to be respected by his family.
"A problem is going to arise if, between now and then, Harry repays him by attacking him, Camilla or the institution. He is not going to put up with inaccurate and unfair attacks," Nicholl told the Daily Beast.
She added: "The ball is in the Sussexes' court. The royals - just like the rest of us - are waiting to see what they will do next."
On Tuesday it was announced the coronation of King Charles III will be held in May where he will be crowned at Westminster Abbey in London.
The ceremony is set to follow the traditional 1000-year pageantry used for anointing monarchs.
"The coronation will reflect the monarch's role today and look towards the future while being rooted in longstanding traditions and pageantry," the palace said in a statement.
