The Queen is currently under medical supervision after doctors became concerned for her health.
Doctors have advised that Queen Elizabeth II remains at Balmoral. The 96-year-old's immediate family members have been informed, with the latest announcement escalating fears for the monarch's health.
The head of state pulled out of a virtual Privy Council on Wednesday after doctors ordered her to rest. A Palace spokesperson said: "Following further evaluation this morning, the Queen's doctors are concerned for Her Majesty's health and have recommended she remain under medical supervision.