A source close to Prince William also told the publication that he wants to support his father”, particularly during “everything the King is going through with his treatment”.

The rift between Prince Harry and his family has been highlighted recently as the Royal Family attending events marking the 80th anniversary of D-Day while the Duke remained in California.

Experts said this will have prompted Prince Harry to reflect on the extent of the poor relations, particularly with his brother, who took a leading role in the commemorations.

Royal historian and expert Dr Tessa Dunlop has said Prince Harry will have been sad to see Prince William fulfill his duties without him. She told The Mirror: “For the Duke of Sussex, looking on from the other side of the Atlantic, there will be some sadness.

“War is raging in the East of Europe right now and the Duke knows his presence not only captures headlines and boosts the Sussex brand, but helps tie war stories from the past to those in the present day.

“Likewise it is a loss for the Royal Family. The ageing King and Camilla with dutiful William know the drill but lack the pizzazz and lived frontline experience that these events thrive on.”