Meghan Markle’s influence over Prince Harry is sure to irritate Queen Elizabeth II.

Duncan Larcombe, a former Royal Editor, said that “mixing Hollywood and royals hasn’t ended well” previously.

Queen Elizabeth II, according to Larcombe, disapproves of the Meghan Effect because it violates royal custom, and the monarch is a “stickler for tradition.” The firm’s members do not endorse any specific celebrity.

“So it is quite new and is probably something I would suggest the Queen would have reservations with,” Larcombe continued.

“It’s a definite break from tradition. We know the Queen is a stickler for tradition.”

This week, it was revealed that Prince Harry is collaborating with the world-famous American broadcaster on a multi-part mental health documentary for Apple.

Harry will appear on screen during the documentary, but it is unclear if he will be interviewed.

He also said that, rather than Markle adapting to the royal family, it appears that Prince Harry is backing her interests.

He said: “It’s obviously another very clear sign, Harry is going along with Meghan rather than the other way around.”

“These new charities and projects he’s got involved with the partnership with Oprah Winfrey is more evidence of ‘The Meghan Effect,’” Mr Larcombe said of the collaboration.

The Duke and Duchess of Sussex have declared that they will keep their baby plans private. At the time, it was unclear where Markle would give birth or when she would give birth. It’s been speculated that she’ll give birth at Frimley Park Hospital. However, according to some reports, she will give birth at home.

Duncan cautioned that blurring the borders between celebrity and royal hasn’t always been a good idea.

He was referring to the backlash Sarah Ferguson has had as a result of her celebrity connections.

He said: “Traditionally when members of the royal family have mixed their causes with celebrity, it hasn’t got particularly well.

“Sarah Ferguson has come under criticism for mixing in celebrity circles.”

“I am incredibly proud to be working alongside Oprah on this vital series which we have been developing together for several months,” Harry said of the Apple documentary relationship with Oprah, which will concentrate on mental illness and mental wellness.

“Our hope is that this series will be positive, enlightening and inclusive – sharing global stories of unparalleled human spirit fighting back from the darkest places, and the opportunity for us to understand ourselves and those around us better.”

Duncan also pointed out that the royals’ collaboration with Hollywood personalities demonstrates Meghan’s power in the relationship.

He said: “It’s evidence of Meghan bringing her own into the relationship. I don’t think this is necessarily a bad thing.

“Harry knew what he was getting into when he married her, or got engaged to a single-minded, ambitious, successful American actress.

“Clearly Meghan is no shrinking violet.”