Royal biographer claims the Queen’s reign is “effectively over” due to the novel coronavirus, “practically putting Charles on the throne” as she is unable to carry out engagements and could be in isolation for some time.

Andrew Morton, the man who exposed Prince Charles’ and Princess Diana’s failed marriage through his book, Diana, Her True Story, said that the virus has “done more damage to the monarchy than Oliver Cromwell.”

Her Majesty, at 94, may remain in self-isolation with limited staff and her husband, Prince Philip, for months and may never return to regular royal duties as she fall under the at risk age bracket.

“It’s terribly sad but I can’t see how the Queen can resume her job. The COVID-19 virus isn’t going away soon and will be with us for months if not years,” Morton said.

“It would be far too risky for the Queen to start meeting people on a regular basis. She has always loved getting out and meeting people but she can’t take the risk.”

Buckingham Palace spokesperson said last month that Her Majesty continues to be “busy”, conducting a weekly audience with the Prime Minister via phone call and continues to receive her daily red boxes of Government papers.

The Queen has also had photographs taken and released of her riding at her pony at Home Park in Windsor, allows releasing of an audio of a call with a nurse and fronted two, extremely rare televised addresses.

Details of a video call were also released for the first time as Her Majesty spoke to unpaid carers to mark carers week.

Her last public engagement was Commonwealth Day service at Westminster Abbey last March, an event that also marked the final official appearance of Prince Harry and Meghan Markle as senior members of the Royal Family.