The Queen was out driving close to Windsor Castle today as she takes a two-week break from duties amid fears for her health after her secret overnight stay in hospital late last month. The images of Her Majesty behind the wheel will ease concerns for the 95-year-old's wellbeing after her aides announced on Friday that she would be taking two weeks off from her duties on doctor's advice. 

That revelation came days after Buckingham Palace was accused of concealing the fact the Queen made a visit to the King Edward VII’s Hospital in central London when officials insisted she was well and at Windsor. Royal aides later admitted the overnight stay was for ‘preliminary investigations’ with the exact reason still unknown. 

Wearing sunglasses and a headscarf, the Queen looked happy and healthy as she left a rear entrance of Windsor Castle in photographs that will bring joy and relief to millions of people worried for her health in Britain and around the world.

As Her Majesty was forced to miss the COP26 conference in Glasgow, the monarch will instead welcome assembled delegates to Britain with a recorded video message with Prince Charles and Camilla (pictured) representing the Royal Family in Scotland this afternoon. 

Prince William is also scheduled to join the royal charm offensive in Scotland. The Duke of Cambridge tweeted: 'COP26 is a landmark moment for the future of our planet — I’m proud that our @EarthshotPrize Finalists will be joining me in Glasgow to show the world that there is reason to be optimistic'.

Her Majesty is reportedly set to stick to low-key online events and virtual audiences this week as she adheres to doctors’ orders as part of her determination to be fit for Remembrance Sunday. Royal sources said that the 95-year-old will follow medical advice ‘to the letter’ after she was advised to cancel all official visits and rest for another two weeks. But the monarch has vowed to attend the service at the Cenotaph on November 14, a long morning involving hours of standing up, with one palace source saying: ‘That’s just unmissable, as far as the Queen is concerned. It is one of her most sacred duties.’

Under rules enshrined in law and detailed on the official Royal website, four members of the family are currently entitled as ‘Counsellors of State’ to take over from the Queen if she is unable to perform her duties – if, for example, she were abroad or unwell. These Counsellors are Prince Charles, Prince William, Prince Andrew and Prince Harry, chosen because they are the four next in line to the throne and at least over the age of 18. This rules out William’s children George, Charlotte and Louis.

But neither Prince Andrew – who is fighting a lawsuit in the US – nor Prince Harry, who has quit official duties and now lives in California, are currently working members of the Royal Family.

Vernon Bogdanor, the author of Monarchy And The Constitution and professor of government at King’s College London, said: ‘A Counsellor not domiciled in the UK cannot act, so that excludes Harry. The next in line and over the required age of 21 would be Princess Beatrice. However, most of the functions of the Head of State can be devolved. It is not, for example, constitutionally necessary for the Queen to attend the State Opening of Parliament.’ Two Counsellors of State are required to act together in a ‘quorum’ to perform crucial functions, such as providing Royal assent to bills passing through Parliament and appointing High Court judges. Without such assent, these functions of Government cannot be enacted.

Dr Craig Prescott, a constitutional expert at Bangor University, said the current situation posed a potential problem for the smooth running of Government. ‘There is a small but genuine risk that the non-availability of Counsellors of State could impede the operation of the constitution. It could certainly make the day-to-day running of Government much more tricky. ‘The Counsellors of State are a Plan B from a constitutional point of view, but what happens when Plan B isn’t quite ideal?'

Dr Prescott continued: The Queen may look to add the Duchess of Cornwall, who would become a Counsellor of State when Charles is King anyway. Or they could go down the line to Princesses Beatrice or Eugenie, or add more members of the family, like Princess Anne or Prince Edward to the list.’ 

A source close to the Palace said: ‘This is a constitutional headache. With an aging monarch there are talks about what will happen if the Queen is unable to work for some reason. You can’t have Andrew and Harry do it and Charles and William are extremely busy.’

There is precedent for Counsellors of State stepping in. During the Queen and Prince Philip’s tour of New Zealand in 1974, the Queen Mother (left) and Princess Margaret (center) enacted the Queen’s wishes to dissolve Ted Heath’s Government.

Mr Johnson yesterday sought to allay any alarm about the Queen, saying the public must ‘respect’ her need to rest for a short period of time. Speaking to ITV News in Rome during the G20 summit, he said: ‘I spoke to Her Majesty, as I do every week as part of my job, and she was on very good form. She has been told by her doctors that she has got to rest, and I think we have got to respect that and understand that. Everybody wishes her all the very best.’

As well as speaking to Mr Johnson, the Queen talked to Chancellor Rishi Sunak ahead of his Budget announcement and recorded a speech at Windsor Castle which will be shown at the COP26 climate change summit in Glasgow tomorrow.

The announcement that the Queen will rest for ‘at least’ another fortnight means she will miss the Festival of Remembrance at the Royal Albert Hall. But she hopes to be fit enough to attend the Remembrance Sunday ceremony at the Cenotaph on November 14. Prince Charles will lay a wreath on behalf of his mother, as he has done in recent years, with the plan for her to again watch from a nearby balcony. Charles will then fly out for an official tour of Jordan and Egypt, effectively leaving William as the only Counsellor of State.

A Royal insider said: ‘The Counsellors of State are there to provide a more temporary stopgap. I expect that quite an extraordinary series of events would be required to lead to a Regency. Her Majesty will be committed to carrying out her duties as long as she possibly can.’ Buckingham Palace declined to comment.