In the case of the Sovereign not being able to attend a Privy Council meeting because of an absence due to travel abroad or temporary illness, two or more members of the Royal Family will stand in as Counsellors of State. Their role is to carry out the functions of the Sovereign.
The first Counsellors of State were created by an Order in Council of George V in 1911.
Under the Regency Act 1937, Her Majesty is able to appoint Counsellors of State.
They have a limited role, although any two Counsellors of State may attend Privy Council meetings and they may sign standard documents. The Counsellors of State cannot, unless on Her Majesty’s exact orders dissolve Parliament or do they have the ability to create peers.
The Counsellors of State are the consort of The Queen and the first four people in the line of succession meeting the qualifications.
Those who are chosen must have reached the age of twenty-one. Although the heir to the throne becomes qualified when they reach eighteen.
The only person to have been a Counsellor of State while not a queen consort, prince or princess was George Lascelles, 7th Earl of Harewood since the 1937 passage of the Regency Act.
The Queen Mother served as Counsellor of State from 1953 until 2002. Upon Prince William turning twenty-one, The Princess Royal’s position ended. The Same for the Earl of Wessex who was a Counsellor until Prince Harry turned twenty-one in 2005.
The current Counsellors of State are: The Duke of Edinburgh, The Prince of Wales, The Duke of Cambridge, Prince Harry of Wales and The Duke of York.
The delegation of powers to Counsellors of State is made by letters patent under the Great Seal of the Realm.