The Queen has postponed her virtual audiences for Thursday after being diagnosed with Covid-19.
It is the second time in a week that she has been forced to cancel engagements after testing positive for coronavirus on Sunday.
The 95-year-old, who is triple-jabbed, also postponed virtual meetings on Tuesday after suffering from cold-like symptoms.
A Buckingham Palace spokesman said: “The two virtual audiences that had previously been scheduled to take place today will now be rescheduled for a later date.
“Her Majesty is continuing with light duties. No other engagements are scheduled for this week.”
She was well enough to hold her weekly audience with Boris Johnson on the telephone on Wednesday.
The diagnosis follows a string of Covid cases among the royal family and the Queen’s Windsor Castle team, with the Prince of Wales meeting the monarch before testing positive for the virus for a second time.
The Duchess of Cornwall was also forced to isolate after contracting the virus.
Concerns for the nation’s longest reigning sovereign have been heightened given her age and recent health scare.
The Queen has a run of high-profile engagements coming up.
She is set to host the Diplomatic Reception on March 2, where she will meet hundreds of members of the Diplomatic Corps at Windsor.
The event has already been scaled back from tiara and white tie to lounge suit and cocktail dress.
Buckingham Palace has yet to comment whether the Queen will still attend.
The Queen is also due to be at the Commonwealth Service at Westminster Abbey on March 14, and then the Duke of Edinburgh’s memorial service, also at the Abbey, on March 29.
The nation’s longest reigning monarch recently spent more than three months resting on doctors’ orders.
In the autumn she pulled out of attending the COP26 climate change summit, the Festival of Remembrance and then the Remembrance Sunday Cenotaph service due to a sprained back. She also missed the Church of England’s General Synod.
The Queen now regularly uses a walking stick and has been pictured looking frailer.
She remarked during a Windsor Castle audience last week: “Well, as you can see, I can’t move.”
Her lights duties as head of state include working from her red boxes, sent to her every day and containing policy papers, Foreign Office telegrams, letters and other State papers which have to be read and, where necessary, approved and signed.
