PALACE advisors are seeking an advance copy of ex-butler Paul Burrell's controversial book on Diana, Princess of Wales, to assess its impact on the Royal Family.

PALACE advisors are seeking an advance copy of ex-butler Paul Burrell's controversial book on Diana, Princess of Wales, to assess its impact on the Royal Family.

It is understood that publishers Penguin have been approached by Buckingham Palace for the book, entitled A Royal Duty, which is due out in America on Monday.

Advisors to the Royals want to see the manuscript first hand before deciding on a strategy.

Extracts, including a claim that Diana feared for her life and spoke of a plot to tamper with the brakes of her car, are being published in the Daily Mirror newspaper.

According to yesterday's Mirror, the Duke of Edinburgh wrote to Diana telling her that he and the Queen "disapproved" of the Prince of Wales's affair with Camilla Parker Bowles.

Much of the book appears to be based on letters written and received by Diana, as well as Mr Burrell's experiences and observations as the Princess's butler and confidante.

The question of copyright of letters written by Diana and members of the Royal Family may be raised although, at present palace advisors are merely seeking sight of the full manuscript.

The Mirror reported that the Duke allegedly told Diana: "I cannot imagine anyone in their right mind leaving you for Camilla.'

He is said to have made the remarks in a letter to the Princess written during the summer of 1992.

The Duke is reported to have written to Diana: "We do not approve of either of you having lovers. Charles was silly to risk everything with Camilla for a man in his position.

"We never dreamed he might feel like leaving you for her. Such a prospect never even entered our heads.'

The newspaper said Mr Burrell's book also contained details of other correspondence in which the Duke allegedly tried to blame Diana for Charles's relationship with Camilla.

He asked her if she could "honestly look into her heart' and say the affair was nothing to do with her behaviour towards him, the newspaper report said.

Yesterday's revelations follow a claim that the troubled Princess wrote to Mr Burrell that she knew of a plot to tamper with the brakes of her car and cause a crash.

In the light of the former butler's claim, French police are reportedly considering reopening the investigation into the circumstances surrounding the car crash which killed Diana and her boyfriend Dodi al Fayed.

Dodi's father, Mohamed al Fayed, has called for an independent public inquiry into the deaths of his son and Diana.

Mr Burrell claimed there had been a "stream" of correspondence between the Duke and the Princess in the wake of the publication of Andrew Morton's book, Diana, Her True Story.

He said the letters had "upset and infuriated" Diana with comments she described as "brutal". But Diana denied the Duke accused her of damaging the monarchy, according to Mr Burrell.

In one letter, the Duke allegedly told the Princess that being married to Charles "involved much more than simply being a hero with the British people".

He was also reported to have told her that jealousy was the 'cancer' within her marriage and said her 'irrational' post-natal behaviour, following the birth of Prince William, had not helped her relationship with Charles.

"The remarks kept punching away at the Princess's ego and spirit, delivered by the man she had held in great respect ever since she married into the family, and that was what bothered her most," Mr Burrell said.

However, he said Diana remained a "great admirer' of the Duke and that she respected his honesty.

"In meeting each other head-on, the Princess and the Duke of Edinburgh had broken down barriers and brought many unspoken issues into the open,' Mr Burrell told the Daily Mirror.

Dodi's father, the millionaire owner of the Harrods department store, said it was now Mr Burrell's "civic duty' to reveal all he knew about the circumstances surrounding the crash.

A spokesman for Royal Coroner, Michael Burgess, reiterated that an inquest would be held in due course, although no date had yet been fixed. So far Clarence House, representing the Prince of Wales, and a spokeswoman for Diana's brother, Earl Spencer, have declined to comment on Mr Burrell's claims.

Publishers Penguin later confirmed that Buckingham Palace had requested a copy of the book.

Spokeswoman, Joanna Prior, said: "The Palace was in touch earlier today on behalf of the Duke of Edinburgh. We have to protect our commercial interests, serialisation rights and so on, and it did not seem appropriate to hand over the whole book.

"We did however deliver, by hand, sections of the book referring to the Duke and sought to clarify the situation."

Asked about possible legal considerations concerning the copyright of the Duke's letters, Ms Prior said: "I don't want to get into that at the moment. We feel very strongly that it is in the public interest that this story is aired.

"Mr Burrell believes that members of the Royal Family and their relationship with Diana have been misrepresented in the past and he wants to set the record straight.'

A spokesman for Mr Burrell said the former Royal butler was unable to comment on the latest developments because he was contracted to the Daily Mirror.