The Queen's upcoming visits to Cheshire and Camden have been postponed because of the coronavirus pandemic, Buckingham Palace has announced.
Heir to the throne the Prince of Wales and the Duchess of Cornwall have already pulled out of their spring overseas tour just days before it was due to begin, raising the prospect that more royal engagements could face cancellation in the coming weeks.
The Queen, 93, was due to visit the Bentley Motors Factory in Crewe, and the Jodrell Bank Observatory and Square Kilometre Array Global Headquarters in Macclesfield on March 19.
She was also due to visit Camden on March 26 but full details of the trip had not yet been released.
A spokesman for the Queen said: "As a sensible precaution and for practical reasons in the current circumstances, changes are being made to The Queen's diary commitments in the coming weeks.
"In consultation with the Medical Household and Government, Her Majesty's forthcoming visits to Cheshire and Camden will be rescheduled.
"Audiences will continue as usual. Other events will be reviewed on an ongoing basis in line with the appropriate advice."
The Queen – the nation's longest reigning monarch – is due to turn 94 next month and the risk of more severe symptoms from the Covid-19 illness is greater for the elderly and those with pre-existing health conditions.
The day of engagements next Thursday would have seen the monarch travel to Cheshire to meet staff and apprentices at the Bentley factory, operate the Lovell Telescope at the observatory and meet local school children engaging in hands on science activities.
The Queen wore large gloves when she handed out honours to recipients at a palace investiture on March 3.
She also avoided shaking hands at the Commonwealth Service at Westminster Abbey and during a one-to-one audience with the Sri Lankan High Commissioner this week, but was back shaking hands with Professor Mark Compton, Lord Prior of the Order of St John, on Wednesday.
England's chief medical officer, Professor Chris Whitty, has said the death rate for people infected with coronavirus is "significantly ramped up" among those over the age of 80.
Charles and Camilla were set to tour Bosnia and Herzegovina, Cyprus and Jordan in just four days' time, but the trip was postponed on Friday at the request of the Government.
A Clarence House spokesman said the decision was taken "owing to the unfolding situation with the coronavirus pandemic".
The prince, 71, and the duchess, 72, are understood to be in good health.
The visit may be replaced with engagements in the UK, but not those involving significant gatherings of people to avoid putting any additional pressure on public services.
It was to be the first official royal visit to Cyprus for 27 years.
Charles was preparing to travel to Bosnia and Herzegovina on March 17 and 18, be joined by Camilla in Cyprus from March 18 to 21, and head to Jordan together until March 25.
His solo visit to Bosnia and Herzegovina was to pay his respects in the 25th anniversary year of the Srebrenica genocide.
As well as the Queen, other members of the royal family have also been altering the way they greet others in the wake of the outbreak of the Covid-19 illness.
Charles has been adopting a namaste rather than a handshake and the Duke of Sussex bumped elbows with musician Craig David at the Commonwealth Service.
It is not yet known whether the incoming state visit by the Emperor of Japan at Windsor Castle in May could be postponed.
The Queen and the Duke of Edinburgh's granddaughter, Princess Beatrice, the Duke of York's eldest daughter, is preparing to marry property tycoon Edoardo Mapelli Mozzi – who has dual British and Italian citizenship – at the end of May.
Italy, the world's worst-hit country after China, is in nationwide lockdown.
Meanwhile, Harry, who is about to quit as a senior royal at the end of the month, has been gearing up for his Invictus Games in The Hague in May.
Current and former servicemen and women from more than 20 countries will gather for the sporting competition if it goes ahead.
Charles held an investiture at the palace on Thursday and Camilla joined racegoers on Ladies' Day at the Cheltenham Festival on Wednesday.
The Queen's daughter the Princess Royal and granddaughter Zara Tindall were out and about enjoying the races at Cheltenham on Friday.
It is not known if the coronavirus pandemic will affect Royal Ascot or the Queen's garden parties later in the year.
More than 8,000 guests at a time mingle on the lawns of Buckingham Palace in London or at the Palace of Holyroodhouse in Edinburgh.
The monarch welcomes more than 30,000 people to her garden parties every year.