The King has returned to royal duties in recent weeks after a successful start to his cancer treatment.

Camilla is said to be worried about Charles’s work rate (Image: Getty)

Queen Camilla is said to be “stressed” about King Charles’s workload as he continues cancer treatment.

The King has returned to royal duties in recent weeks after a successful start to his treatment but according to royal expert Rafe Heydel-Mankoo, Camilla thinks he is doing too much.

Charles returned to his usual work on April 30 and last week hosted a garden party for 7,000 people at Buckingham Palace.

On Monday he visited an army base for an emotional joint engagement with his son, Prince William, where he handed over a key military role to him.

Speaking on GB News, Mr Heydel-Mankoo said: “The Queen has said that if he behaved better, he’d be improving far more rapidly.

King Charles has returned to royal duties following cancer treatment (Image: Getty)

“I think she might be a bit stressed at the number of activities he’s done I mean, just in the last week he went to Middle Wallop in Hampshire to an air base to hand over to Prince William, the colonel in chief of the Army Air Corps.

“He has hosted a garden party for 4000 people from the creative industries.

“He’s attended a service at Saint Paul’s Cathedral for the order of the British Empire, and he made a surprise visit to the Royal Opera House on Thursday, where he seemed to be in very good spirits too.

“So I think we should all take some good heart from His Majesty. This is clear progress.”

Buckingham Palace has already confirmed that “forthcoming engagements will be adapted where necessary” to accommodate the King’s recovery following his cancer treatment.

King Charles, Queen Camilla, and Prince William will also commemorate the 80th anniversary of D-Day on June 5 and 6.

Mr Heydel-Mankoo also revealed that it is “unlikely” that Princess Kate will attend the event as she recovers from her own cancer diagnosis.

He said: “Last year she was there, resplendent in a green dress and we’re waiting to see whether she will also be attending this time or not.

“But there’s been no mention of her attending the D-Day ceremonies, although the Prince of Wales will be attending the Canadian beach Juno, and also at the Omaha Beach, where the international heads of state, but no word of the Princess of Wales attending that.”