The Prince of Wales, the Queen and other working royals will step up their royal duties while the King undergoes treatment for a form of cancer.
Buckingham Palace has confirmed a number of the King’s forthcoming public engagements will have to be rearranged or postponed, but it is not anticipated that Counsellors of State will need to be appointed.
In the event a monarch cannot undertake their duties as sovereign on a temporary basis due to illness, two or more Counsellors of State can be appointed by Letters Patent to act in their place.
It is hoped the King will continue with some of his duties, but how much he can do will depend on the progress of his treatment and the orders of his doctors.
Other members of the royal family are expected to continue with a full programme of public engagements and may undertake some additional duties on behalf the King if they are required to do so.
Usually the duty would fall to William in the first instance, who has recently returned to royal duties after the Princess of Wales underwent major abdominal surgery last month.
William had taken time off to support his family as Kate recovered first in hospital, then returned home to Windsor to convalesce.
He will host an investiture ceremony at Windsor Castle on Wednesday and that evening will attend the London Air Ambulance annual fundraising gala in central London, Kensington Palace said.
Camilla will also continue with a full programme of public duties while her husband is treated, the Palace said.
Provisions for Counsellors of State are made under the Regency Acts 1937 to 1953 and those who can currently stand in for Charles include Queen Camilla and the four most senior adults in the line of succession over the age of 21 – the Prince of Wales, the Duke of Sussex, the Duke of York and Princess Beatrice.
In 2022, the King asked Parliament to add his youngest brother the Duke of Edinburgh and sister the Princess Royal as extra Counsellors of State so they can deputise for him if need be, and the addition was fast-tracked into law.
The legislation did add Anne and Edward to the list, but stopped short of removing Andrew and Harry. However, the House of Lords heard only “working members” of the royal family would be called upon to act as Counsellors of State.
The Duke of Sussex is flying to London to be with his father after the King’s shock cancer diagnosis.
But Harry is not expected to take up any royal duties.
Charles is positive about his treatment and hopes to returning to full public duty as soon as possible, the Palace said.