Sarah Goodall (pictured), a former secretary in Prince Charles’s office, is threatening to publish a first-hand account of various events she witnessed including, the break-up of his marriage to Diana and his affair with Camilla Parker Bowles.

Her 320-page book, The Palace Diaries: The True Story of Life Behind The Palace Gates, is to be published in September by Mainstream, an Edinburgh-based publisher, priced at £12.99 ($24). The title is already being heavily promoted with chain booksellers and on Amazon.

In the book, the author claims that Camilla targeted her as being “too close” to the Prince and identified her as a threat who “had to go”.

Clarence House sources say that she may have to fight it out in court as the Prince is preparing to injunct its publication.The Daily Mail reveals that Royal solicitors Harbottle and Lewis have demanded that the publishers hand over a copy of the book before publication.

“She is also planning to talk in depth about the ‘Rasputin-like’ hold that Charles’s former valet, Michael Fawcett, still has on him and highlights the ‘frigid’ relationship that he has with his father, the Duke of Edinburgh.”

A source said, “The Prince’s lawyers are looking into the possibility of legal action at the moment and have asked to see a copy of the book to see how damaging it is before they consider sending the big guns in.”

“Sarah [Goodall] signed several confidentiality agreements during her employment so they are very keen to see what she has written. An injunction is not out of the question.”

Mainstream has refused to comment, but said: “We aren’t going to go quietly. We will still intend to have a number of overseas editions of the book printed. It will be just like Spycatcher.”

The Mail reports: “She was even awarded an MVO (Member of the Victorian Order) for her loyalty and discretion.”