First, King Charles can delegate some or most of his royal functions to counsellors of state, as happens most commonly when he is travelling overseas. Two counsellors of state act jointly in exercising royal powers such as assenting to laws, receiving ambassadors and holding Privy Council meetings.
The counsellors of state are the spouse of the sovereign and the next four adults in line of succession to the throne – being Queen Camilla, Prince William, Prince Harry, Prince Andrew and Princess Beatrice.
However, Prince Harry is excluded while he is outside the United Kingdom, and in practice Prince Andrew and Princess Beatrice are not called on to act as they are not “working royals”.
As this left only Queen Camilla and Prince William to perform the role, a law was passed in the UK in 2022 to add Princess Anne and Prince Edward to the list.
Counsellors of state may carry out most of the sovereign’s functions while he is ill, but they cannot dissolve Parliament, except on his instruction, and they cannot create peers. Whether they can appoint a prime minister remains a matter of debate. Most significantly, they cannot exercise powers with respect to the King’s other realms, such as Australia.
Regency
The second option is a regency. This occurs if the King “is by reason of infirmity of mind or body incapable for the time being of performing the royal functions”. The sovereign does not control when or for how long a regency occurs. Instead, it is initiated by a declaration of three or more of: the sovereign’s spouse, the lord chancellor, the speaker of the House of Commons, the lord chief justice of England and the master of the rolls.
The UK’s Regency Act requires Prince William to be regent, as he is the next adult in line of succession to the crown. The regent has the powers of the King with respect to the United Kingdom, but cannot change the order of succession to the crown.
The Regency Act does not give the regent powers in relation to realms such as Australia and New Zealand. New Zealand resolved the problem by inserting a section into its Constitution Act which provides that whoever is made regent under the law of the UK may perform the royal functions of the sovereign with respect to New Zealand. Australia, however, has done nothing in this regard, so a British regent would have no powers with respect to Australia.
Abdication
The final option for an incapacitated monarch is abdication. This leads to difficult questions about how an abdication would operate in relation to each of the realms.
When King Edward VIII abdicated in 1936, it was achieved by both a signed instrument of abdication and the enactment of legislation to which the various realms, including Australia, assented. This is not possible today, as the UK can no longer legislate with respect to Australia.
Abdication would therefore raise difficult questions about whether there needed to be a separate abdication of the King of Australia, to trigger the application of the rules of succession that are now part of Australian law, or whether covering clause 2 of the Constitution, which defines the sovereign by reference to Queen Victoria’s “heirs and successors in the sovereignty of the United Kingdom”, would apply.
Because of the potential constitutional messiness of dealing with the King’s role in his 14 realms beyond the United Kingdom, it is likely abdication would be avoided.
