Paul Burrell's A Royal Duty is released after the author shrugged off Princes William and Harry's accusations of a "cold and overt betrayal" of their dead mother, Princess Diana.
In a television interview to be broadcast on Monday, Diana's former butler said that "just one phone call" would have stopped him from publishing.
Serialised in a British tabloid over the past week, teasing excerpts from Burrell's book included a letter written by Diana predicting her own death in a car crash - 10 months before she was killed in a Paris tunnel.
The excerpts have triggered a heated exchange between the royal family and Burrell, who was Diana's servant, friend and confidant for more than a decade.
Many commentators have criticised him for "cashing in" on Diana's memory through the book published by Penguin.
Burrell's book delves into Diana's personal life, the break up of her marriage with Prince Charles and her private correspondence.
It has also stirred new controversy over the events surrounding her death, leading some royal-watchers to call for a full British inquiry.
Burrell is expected to make a
mint out of his book
Diana, her lover Dodi al Fayid and their chauffeur Henri Paul died when their Mercedes crashed at high speed in a tunnel in Paris in August 1997.
Last week, Diana's sons William and Harry issued a stern statement criticising Burrell and saying: "We cannot believe that Paul, who was entrusted with so much, could abuse his position in such a cold and overt betrayal".
The BBC said that Burrell, in a television interview to be broadcast on Monday night, would hit back by telling the two princes to "grow up".
Asked about the princes' criticism of his decision to publish the letters, Burrell says in the BBC interview: "I felt immediately that those boys were being manipulated and massaged by the system, by the palace, by the grey men in suits, by those who did exactly the same to their mother."
"We have to grow up and get on with it and the boys are now adults. They're not children any more and their mother will be talked about."
Burrell stood trial last year accused of stealing hundreds of Diana's belongings, including jewellery and clothes, but the case collapsed dramatically when the Queen stepped in and wrecked the prosecution case.
She said she remembered Burrell telling her after Diana's death that he would look after some of her belongings.