Admiral Timothy Laurence, 66, tested positive for coronavirus on Wednesday.

A royal source said the Princess Royal, 71, and her husband will now not be spending Christmas with the Queen as they will be isolating.

It comes as the 95-year-old monarch prepares for her first Christmas since the death of the Duke of Edinburgh in April this year.

Earlier in the week, it was announced she will be spending the day at Windsor Castle - instead of her usual tradition to go to Sandringham.

The Queen usually hosts her family at Sandringham in Norfolk, with crowds of wellwishers turning out to watch the royals walk to the Christmas Day service at St Mary Magdalene Church on the estate.

It is not yet known where the Prince of Wales, the Duchess of Cornwall and Duke and Duchess of Cambridge will be spending Christmas.

Last week, it was revealed the Queen had cancelled her pre-Christmas family lunch due to be held on Tuesday.

The annual event allows members of the family who cannot travel to Sandringham to spend time with the monarch but last year’s lunch was also cancelled because of the pandemic.

It is understood the decision to cancel the lunch was a precaution due to surging Omicron cases.

The Queen also spent last Christmas at Windsor where she and the Duke of Edinburgh, her husband of 73 years, stayed shielded throughout lockdowns.