“We will forget her very soon”: the phrase Diana's brother attributes to Charles III that has infuriated Buckingham

Buckingham Palace has flatly denied the claim by the late Princess Diana's brother that King Charles III said she would soon be forgotten following her death.

In a new book, Charles Spencer recounts the traumatic days following the death of Diana, who passed away in a car accident in Paris in 1997 at age 36. He claims that he argued with then-Prince Charles—who was separated from Diana—over palace plans for the couple's two sons, Princes William and Harry, to walk behind their mother's coffin during the funeral procession.

Spencer maintains that he told the now-king that Diana would not have wanted her sons, who were 15 and 12 at the time, to go through such a difficult experience. He claims that Charles responded to him, “Don't worry, we will forget her very soon,” and accuses him of feeling “contempt” for his ex-wife.

The Daily Mail newspaper is publishing excerpts from Spencer's book, “Swan Song: Diana, My Sister,” which is scheduled to go on sale next week.

Buckingham Palace responded to the claims on Wednesday night with an extremely blunt statement, considering the measured standards of the royal household.

“While we do not comment on books as a matter of principle, his majesty is aware that the grief over the loss of a sibling can cloud reasoning, affect judgment, and distort memories in ways that others do not recognize, even many years after such a loss,” it noted.

The tensions between the palace and Diana's aristocratic relatives, the Spencers, after her death have been widely commented upon and were dramatized in the film “The Queen” and the television series “The Crown”.

Many felt that Buckingham was slow to acknowledge the worldwide outpouring of grief over Diana's death, which forced the royal family to admit that Diana's closeness to the people had reached the public in a way that had eluded the rest of the institution. The more sensitive approach of William and Harry—and, in recent years, of the king—is a legacy of that time.

Prince Charles, then 32, married Lady Diana Spencer, 20, in a lavish ceremony at St. Paul's Cathedral in 1981. The couple separated in 1992 and divorced in 1996.

Diana's younger brother, Charles Spencer—the 9th Earl Spencer—has long been at odds with the royal family over their treatment of his sister.

In a moving eulogy during the funeral, Spencer vowed that Diana's “blood family” would continue her “imaginative and loving” legacy in raising her two sons. The speech was widely regarded as an attack on the royal family.