THE Queen has pulled out of tonight's star-studded Royal Variety Performance after failing to shake off her chest infection.
Camilla, 77, is suffering "lingering post-viral symptoms" and doctors have ordered her to rest.
Royal sources insist she is "naturally disappointed" but there is not said to be any cause for alarm.
It comes after she pulled out of Remembrance events two weeks ago due to her chest infection and was seen coughing during her most recent engagements.
The King, 76, who has cancer, will attend the gala event hosted by Amanda Holden and Alan Carr at Royal Albert Hall.
A Buckingham Palace spokesperson: "Following a recent chest infection, The Queen continues to experience some lingering post-viral symptoms, as a result of which doctors have advised that, after a busy week of engagements, Her Majesty should prioritise sufficient rest.
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"With great regret, she has therefore withdrawn from attendance at tonight’s Royal Variety Performance.
"His Majesty will attend as planned."
Camilla was struck down with chest infection after returning from her nine-day tour with Charles to Samoa and Australia.
She pulled out of several engagements including Remembrance services and Gladiator II premiere.
But returned to scaled back jobs including a Booker Prize reception at Clarence House where she said she was "on the mend" and "getting much better".
Palace sources say a decision not to attend was taken as the event runs late into the evening.
And doctors have said recovering patients should not be overstretched.
Camilla is expected to spend the weekend in Sandringham with the King.
It is believed to be a nasty bug rather than any major health scare.
A Royal source said the Queen was "naturally disappointed to miss the evening's entertainments, and sends her sincere apologies to all those involved, but is a great believer that 'the show must go on'.
"She hopes to be back to full strength and regular public duties very soon."
