According to the statement from the palace, "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 ...

Buckingham Palace has issued an update on the Queen's health after she was forced to pull out of a major royal event – and a doctor has now shed some light on her condition

It is understood Camilla will remain in London on Friday and will then travel to Sandringham for the following week as planned. 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'.