The Queen has withdrawn from her engagements for the rest of the week after falling unwell with a chest infection, Buckingham Palace has announced.

Camilla, 77, who has not long returned from a busy official overseas tour to Australia and Samoa, is understood to be resting at home.

The update comes after a year of difficult health troubles for the royal family, with both the King and the Princess of Wales being diagnosed with cancer.

A Buckingham Palace spokesperson said: “Her Majesty The Queen is currently unwell with a chest infection, for which her doctors have advised a short period of rest.

“With great regret, Her Majesty has therefore had to withdraw from her engagements for this week but she very much hopes to be recovered in time to attend this weekend’s Remembrance events as normal.

“She apologises to all those who may be inconvenienced or disappointed as a result.”

The Duchess of Gloucester has stepped in on the Queen’s behalf to attend the annual opening of the Field of Remembrance at Westminster Abbey on Thursday.

Camilla has also pulled out of a Buckingham Palace reception for Olympic and Paralympic athletes hosted by the King the same evening.

It is understood the Queen is currently resting at home.

No further details regarding her illness or treatment have been released but she is understood to be under doctors’ supervision.