When King Charles celebrated his 75th birthday, it was understood that Prince Harry called his father in a gesture of goodwill.
The commentator added: “But then Endgame was released by an individual who has been very closely identified with the couple, even if he personally denies he’s Meghan’s mouthpiece.”
The royal expert suggested the new revelations paused any kind of mending between the two sides.
He added: “There’s already a very deep rift. We were only at the beginning of possibly mending it. So, clearly, these revelations will deepen the rift.
“As far as for good, there’s no such thing because you never know what’s coming. Nobody knew this was coming.
“The King and the Sussexes were experiencing bitter relations, there’s no doubt about it. It depends on what the couple do and how this plays out.”
No member of the Royal Family, nor Prince Harry or Meghan Markle have commented on the explosive claims.