Princess Diana would be devastated by William and Harry's feud, says royal author

Princess Diana would have wanted nothing more than Prince William and Prince Harry to be best friends and support each other as they grew up, according to a royal source.

"Diana said to me quite clearly on several occasions that she saw Harry as the wingman for William in what ultimately would be a very solitary, sombre job as future king," shared Andrew Morton on an episode of the U.K. talk show Loose Women.

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"She would have been very upset at the way these two have split apart," added Morton.

The author, who worked with the late Princess of her biography, Diana: Her True Story, says he thinks she would have tried to help mend their relationship.

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"Knowing [the brothers'] personalities intimately, as a mother would do, she would be working out, perhaps with Prince Charles by her side, a way to reconcile them," he guessed.

William, 39, and Harry, 36, will be reunited to attend the installation of a statue of Diana, Princess of Wales, at Kensington Palace in London on July 1, on what would have been Diana's 60th birthday.

They last saw each other at their grandfather, Prince Philip's funeral in April, where it was reported an argument broke out between the brothers behind closed doors, proving there's still some healing to be done.

READ MORE: Prince Harry and Prince William started arguing 'immediately' at Prince Philip's Funeral

The Duke of Sussex returned to the UK on Friday, June 25, local time. He made the trip alone, leaving his wife, the Duchess of Sussex at home in California with their two children Archie, two, and Lilibet, who was born on June 4.