But for a regency to commence, the Queen would need to become too old and infirm to rule.
The Constitution Unit said: “The Regency Acts 1937 and 1953 established a procedure for declaring that the Queen has become incapable by reason of infirmity of mind or body.
“The people who can make a declaration of incapacity are at least any three of the Queen’s consort (Prince Philip), the Lord Chancellor, the Speaker of the House of Commons, the Lord Chief Justice, and the Master of the Rolls.
“Any declaration of incapacity needs to be supported by medical evidence.”
