Britain's King Charles asked Parliament on Monday to amend the law to allow two more of his siblings to act on his behalf when he cannot fulfil official duties.
The House of Lords heard a statement read on the king's behalf. Counsellors are usually selected from the monarch's spouse and the four adults next in line to the throne.
They can act on behalf of the king in his absence to carry out all but his most key roles, such as appointing a new prime minister.
That means that in addition to Charles's wife Camilla and his eldest son and heir Prince William, the group comprises the king's younger son Prince Harry, younger brother Prince Andrew, and Andrew's eldest daughter Princess Beatrice.
That has led to criticism from some commentators because neither Prince Andrew nor Prince Harry carry out official royal roles any more.
Prince Andrew was stripped of most of his titles and removed from royal duties due to a scandal over his friendship with the late US financier Jeffrey Epstein, a convicted sex offender.
The prince later settled a US lawsuit in which he was accused of sexual abuse.
Meanwhile, Prince Harry stepped down from royal duties in 2020 and moved to California with his wife Meghan.
"To ensure continued efficiency of public business when I'm unavailable, such as while I'm 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 … to be increased to include my sister and brother," the king's statement said.
The change will require Parliament to amend the terms of the Regency Act.