Buckingham Palace is taking extra precautions to protect the health of the Queen and other senior royals amid the ongoing coronavirus pandemic.
The monarch will be going to Windsor Castle for her Easter break a week early this year and is likely to remain there much longer than usual.
Should the Queen fall ill, there are procedures in place to make sure duties can continue as her children and grandchildren step in.
Counsellors of state are authorised to carry out most official duties of the Queen, like attending privy council, or signing documents.
There are five counsellors – the monarch’s spouse and the first four in line to the throne, as long as they are over 21.
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Prince Philip has retired from public duties, so it’s unlikely he would be taking on responsibilities to replace a sick queen.
The heir to the throne is Prince Charles. In ordinary circumstances he would take on the Queen’s tasks, but at the age of 71, he is in a high-risk group for contracting Covid-19, according to the government.
That would mean Charles and his wife Camilla, 72, if following official guidelines, would not be able to leave the house frequently, practising social distancing for all but essential tasks and to get some exercise.
The next in line to the throne is Prince William, who would have to pick up some of the slack.
His children, or issues, are far too young to hold the responsibilities of counsellors of state.
But because of his place in the order of succession, Prince Harry is still a counsellor of state.
Harry’s son Archie is also too young, which means Prince Andrew is still a counsellor of state.
Three of the five counsellors of state are currently either retired or have stepped back from royal duties, with Harry quitting as a senior member effective from 31 March, and Andrew taking a back seat in November 2019.
Prince Harry is also said to be taking necessary precautions, having potentially come into contact with coronavirus while in the UK on his farewell tour.
Harry hugged Lewis Hamilton when the pair opened the Silverstone Experience. Hamilton had been in contact with Idris Elba, who has tested positive for coronavirus.
Nevertheless, the royal website still lists Philip, Harry and Andrew as counsellors.
Being a working royal is not a requirement of counsellor of state.
If Andrew, who is the Duke of York, were to take over any duties, it would prove controversial.
He has not taken on any engagements since November, after a disastrous interview with BBC Newsnight about his friendship with the disgraced financier Jeffrey Epstein.
He stepped back for the foreseeable future because of the distraction the friendship caused his family.
Since then he has been keeping a low profile, and reportedly hired expert legal advisers. He has been accused by the prosecutor in the Epstein case of failing to co-operate with US authorities.
Should the Queen become ill during the coronavirus pandemic, it is more likely that the majority of the work would be carried out by Charles and William.
The counsellors do not have as extensive powers as the Queen. For example, they could not dissolve parliament or appoint a prime minister.
They also don’t tend to deal with Commonwealth matters. However, it could be that in the exceptional circumstances, and given Prince Charles is to take over anyway, there is a different approach taken.
The Queen will leave for Easter Court in Windsor on 19 March, a week early. Many of her planned engagements have been cancelled or postponed and the investiture ceremonies will be rearranged.
Prince Charles has postponed his planned tour to Bosnia and Herzegovina. He was to be joined by his wife Camilla for a tour in Cyprus and Jordan but that is also postponed.