Palace fears more revelations from butler

As a royal footman his duties once included walking the Queen's nine corgis. Yesterday, Paul Burrell was playing a more dynamic role, that of the House of Windsor's nemesis.

Some 24 hours after the former butler of Diana, Princess of Wales claimed she had feared she would be murdered, Buckingham Palace said it had asked to see a copy of his forthcoming book to consider its "legal implications".

The serialisation in the Daily Mirror of Mr Burrell's memoirs, which is expected to earn him £1.5m, entered its second day with the disclosure of letters in which the Duke of Edinburgh criticised Diana and the Prince of Wales for the breakdown of their marriage.

The revelation of the Princess's relationship with her father-in-law has provoked alarm in royal circles about the amount of further damage Mr Burrell could inflict.

Until yesterday, the Palace had maintained a dignified silence on Mr Burrell's book, A Royal Duty, the first 100,000 copies of which arrive in bookshops on Monday. But a Palace spokeswoman then said: "We will be looking at the legal implications once we have seen a copy of the book itself."

Palace lawyers are understood to want to focus on confidentiality agreements, obligatory for all members of the Royal Household, signed by Mr Burrell during his employment first as a footman to the Queen and then as valet to Charles and Diana.

One royal source said: "Obviously his lawyers have found a way of being able to publish what they have."

Representatives of Mr Burrell declined to comment on any confidentiality agreement but insisted that he had no intention of undermining the monarchy. A spokesman said: "Paul has made it very clear that he remains a very strong supporter of the Royal Family and is loyal to them."

Supporters of Mr Burrell, who considers himself the guardian of the Princess's reputation, claimed the disclosure of Prince Philip's letters to Diana would enhance his public standing by proving he was not always hostile to her.

Writing in the summer of 1992, shortly after publication of Andrew Morton's book Diana, Her True Story, with which the Princess secretly co-operated, the Duke of Edinburgh wrote: "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. I cannot imagine anyone in their right mind leaving you for Camilla. Such a prospect never even entered our heads."

The letter was signed: "With dearest love, Pa."

Mr Burrell claimed the letter was part of a long correspondence in which Prince Philip established himself as a "firm but fair" arbiter in the disintegrating relationship between Charles and Diana.

In another letter, the Duke of Edinburgh is alleged to have written: "Can you honestly look into your heart and say that Charles's relationship with Camilla had nothing to do with your behaviour towards him in your relationship?"

The disclosure of the correspondence followed the claim that Diana had predicted her death in a car crash. In a letter written by the Princess 10 months before her death in a Paris underpass in August 1997, she said there was a plot by a named individual to tamper with the brakes of her car to allow Charles to remarry.

Meanwhile Penguin, which secured publication of the book with a six-figure advance, said it believed the title would be a bestseller despite its five-day serialisation in the newspaper, which said it had sold an extra 200,000 copies on the first day.

The book publisher said it had firm orders from retailers for 90,000 of the 100,000 copies in its initial print run.