Originally Posted by Spheno
"unplanned manner" doesn't mean "permanent". regency is a permanent thing.
and there are situations when people spend days in artificial coma as part of their treatment.
Regency is NOT permanent. George IV served at least two terms as Regent when his father was incapacitated. George III recovered at least once and so took back the reins as King.
In an 'unplanned' situation - such as an accident resulting in a temporary coma there would be no Letters Patent issued to create CoS's so while in that coma, if no temporary regency is possible then no business is possible - which is why a temporary regency is possible. CoSs can only serve when Letters Patent are issued and stating for what specific purpose/s so in March this year Charles and William were CoSs specifically to Open Parliament and for no other purpose.
Say Charles was travelling to Sandringham and was involved in a car accident that saw him in a coma for six months. As he didn't sign Letters Patent creating William and Anne as CoS for those six months no business of the monarchy could take place so no laws signed into law, no High Commissioners or Ambassadors able to take up their offices etc. Now establishing a Regency which can be done quite easily with the agreement of three of Camilla, The Lord Chancellor, Speaker of the House of Commons, Lord Chief Justice and Master of the Rolls.
The Regency Act clearly says that a regency will be established if 'the Sovereign is by reason of infirmity of mind or body incapable for the time being
of performing the royal functions or that they are satisfied by evidence that the Sovereign is for some definite cause not available for the performance of those functions'. i.e. it can be a temporary situation.