The Princess Royal and the Earl of Wessex will join members of the royal family who can stand in for the King when he cannot fulfil official duties in a move that will make it even less likely that Prince Harry and Prince Andrew will be called to do so.

King Charles’ intention was announced in a signed message read to the House of Lords by the Lord Chamberlain, Lord Parker of Minsmere, who is the most senior official in the royal household.

Charles said the aim of the increase was to ‘ensure continued efficiency of public business when I am unavailable’.

Counsellors of State, who can deputise for the monarch if he is overseas on an official trip or ill, include the Duke of Sussex, who lives in California after stepping down as a working royal, and the disgraced Duke of York.

This comes after rising calls for Princess Anne to receive an exemption from parliament to act on behalf of the King despite rules which prevented her from doing so. 

Prince William, Prince of Wales and King Charles arrive to attend the Remembrance Sunday ceremony at the Cenotaph on Whitehall in central London yesterday.

Princess Anne, Princess Royal during the National Service Of Remembrance at The Cenotaph yesterday

Provisions for the counsellors are made under the Regency Acts 1937 to 1953 and those who can currently stand in for Charles include the Queen Consort, and the four most senior adults in the line of succession – Prince of Wales, Harry, Andrew and Princess Beatrice.

Speaking at the despatch box in the upper chamber, Lord Parker said he had the honour to present a message from the King ‘signed by his own hand’.

The independent crossbencher told peers: ‘The message is as follows: “To ensure continued efficiency of public business when I am unavailable such as while I am undertaking official duties overseas, I confirm that I would be most content, should Parliament see fit, for the number of people who may be called upon to act as Counsellors of State under the terms of the Regency Acts 1937 to 1953 to be increased to include my sister and brother – the Princess Royal and the Earl of Wessex and Forfar – both of whom have previously undertaken this role”.’