Phil Dampier told The Sun: “[William] was going on about their childhood when Diana took them to various charities and so he had to mention [Harry]. It’s as simple as that.

“It would have been a snub if he hadn’t.

“I don’t see it as any sort of major breakthrough, I’m afraid, in their relationship.

“Which is sadly, as far apart as ever.”

Elsewhere, Mr Dampier told the outlet the princes’s mother, the late Princess Diana, would be devastated over them not working together on a project that was so close to her heart.

He said: “I’m sure Diana would be obviously devastated to see what’s happened between the two brothers.

“She’d obviously be very upset to see that they’ve drifted apart so much and have fallen out so badly.

“They both could have done so much good for something which she was very anxious for them to do and so I’m sure she’d be absolutely devastated.”