“I understand she thinks of this as a sacred task… It’s a conflict because most of the world sees the Royal Family as a branch of showbusiness,” she told the Telegraph Magazine.
Reflecting on the death of the Duke of Edinburgh, Dame Hilary said that most people sought routine and were “able to mourn in a natural way”, but recent events show “how far the Monarchy’s arrangements with the media have turned it into a self-punishing institution”.
“No other family would be expected to parade a very elderly, newly widowed lady before the TV cameras, and yet it’s taken for granted that’s what will happen – just as it’s taken for granted that a new Royal mother will appear beaming on the hospital steps within a day of giving birth,” she said.
“There’s no legitimate public interest behind it.”
Questioned about the Monarchy’s future, she added: “I think it’s the endgame. I don’t know how much longer the institution will go on.
“I’m not sure if it will outlast William. So I think it will be their last big era.”
Last month Dame Hilary made headlines after she dismissed Kate Middleton as a personality-free “shop window mannequin” with a “plastic smile” whose “only point and purpose” was to give birth.
She later said that her comments, made at a lecture at the British Museum, were taken out of context.
"My lecture and the subsequent essay was actually supportive of the Royal Family and when I used those words about the Duchess of Cambridge, I was describing the perception of her which has been set up in the tabloid press,” Dame Hilary said at the time.
"My speech ended with a plea to the press and to the media in general. I said ‘back off and don’t be brutes; don’t do to this young woman what you did to Diana’.
"My whole theme was the way we maltreat royal persons, making them one superhuman, and yet less than human."