Broadcaster John Sergeant has hit out at The Crown, saying the royal drama is a sign of "dangerous times" for the monarchy.
Sergeant, 75, said the "deal", in which the Windsors were expected "to be royal and distant" had "broken down".
He said that portraying them in the lavish, big-budget Netflix drama could be a "hazard".
The former political journalist told Radio Times magazine: "These are dangerous times for the Royal Family.
"In the past there has been an implicit deal between us and them. We expect them to be royal and distant, and they in turn are not expected to answer back and complain if the media coverage is excessive or plain wrong.
"This 'deal' now seems to have broken down and I'm concerned about the way the family is portrayed in The Crown.
"Indeed, I'm not sure they should be portrayed at all in a multi-million blockbuster of this sort."
The veteran broadcaster said: "Alongside some moments when timelines and events are massaged and altered to allow for dramatic cohesion, it also suggests that the Queen may have had an affair with her racing manager, Lord Porchester."
The Queen's former press secretary Dickie Arbiter has criticised the suggestion as "totally unfounded".
But Sergeant told Radio Times: "The more skilful the casting, the more adept the direction, the more stunning the costumes, the greater the danger that people will believe they're being told the truth."
He said: "There used to be clear rules about depicting people who are still alive. In books, plays and films we were told that the characters had been made up and bore no resemblance to real people.
"In the case of The Crown, we're being invited to imagine the opposite is true, that this is how the Queen and her family have actually behaved.
He added: "I think we're now asking too high a price of the royals."
Buckingham Palace has said about The Crown: "The Royal Household has never agreed to vet or approve content, has not asked to know what topics will be included, and would never express a view as to the programme's accuracy."
The full interview is in this week's Radio Times magazine.