The Queen is unwell with a chest infection and has withdrawn from her engagements this week, Buckingham Palace has announced.

A palace spokesperson said Camilla's doctors "have advised a short period of rest" and added that "with great regret, Her Majesty has therefore had to withdraw from her engagements for this week".

They added the Queen "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," they said.

It is understood the Queen is currently resting at home and is under doctor's supervision.

Birgitte, the Duchess of Gloucester, has stepped in on Camilla's behalf to attend the annual opening of the Field of Remembrance at Westminster Abbey on Thursday.

The Queen has also withdrawn from a Buckingham Palace reception for Olympic and Paralympic athletes hosted by the King on the same evening.

Camilla recently returned from an overseas tour of Australia and Samoa. No further details regarding her illness or treatment have been released.