Charles is expected to amend the "Regency Act" to add his brother Edward, the Earl of Wessex, and his sister Anne, the Princess Royal, The Daily Telegraph and the BBC reported, quoting sources.

The Telegraph reported the amendments could go before parliament "within weeks", quoting "royal insiders" as saying it was a "logical step". 

Buckingham Palace has not commented officially.

Currently the list of royals who can temporarily take over on the 73-year-old monarch's behalf if he is away or ill only includes Charles's wife Camilla, heir to the throne Prince William, Harry, Andrew and his daughter Beatrice, who is not even a working royal.

A longer list would allow the Palace to bypass Harry, who has quit as a working royal and lives in the US, and Andrew, who has retired from public life over his friendship with convicted paedophile Jeffrey Epstein and allegations of sex with a minor, without directly excluding them.

Daily Express royal reporter Richard Palmer tweeted that amendments "to create more stand-ins for the King is now a priority, sources have confirmed".

He said this would mean "the King never has to ask non-working royals such as Harry, Andrew or Beatrice to stand in for him".

The role includes signing documents and receiving ambassadors, the BBC said.

The regency issue was raised in the House of Lords Monday, with Labour peer Stephen Benn questioning the current situation where Andrew and Harry can exercise these powers. 

"Is it not time for the government to approach the King to see whether a sensible amendment can be made to this Act?" Benn asked.

Senior Tory peer Nicholas True appeared to confirm such discussion, saying that the government "will always consider what arrangements are needed to ensure resilience in our constitutional arrangements".

He added that "in the past we have seen that the point of accession has proved a useful opportunity to consider the arrangements in place".

Queen Elizabeth II suffered ill health during the last year of her life.

She asked Charles to deputise for her at events such as the opening of parliament, showing that the legislation is "still very relevant", Benn said.

Meanwhile, publisher Penguin Random House said on Thursday that Prince Harry's memoir will be published on Jan. 10 with the title "Spare" and will tell with "raw unflinching honesty" his journey from "trauma to healing".

The book, which was originally due to be published later this year, will be "full of insight, revelation, self-examination, and hard-won wisdom about the eternal power of love over grief", the publisher said.

The title refers to Harry's position as the younger brother of Prince William, who has been heir to the British throne since their father Charles become king last month following the death of Queen Elizabeth. Until William and his wife Kate had their three children, Harry was next in line to his brother in the order of succession, hence the phrase "the spare to the heir".

A photo of Harry looking directly into the camera features on the cover, along with the words "Prince Harry" and "Spare".

Harry and his wife Meghan, who are formally known as the Duke and Duchess of Sussex, stepped down from royal duties in early 2020 and moved to the United States