After being moved to a different hospital where he'll remain until "at least" the end of the week, there are mounting fears over the state of Prince Philip's health.
The 99-year-old Duke of Edinburgh was transferred today from King Edward VII's Hospital to St Bartholomew's Hospital, a statement from Buckingham Palace announced, "where doctors will continue to treat him for an infection, as well as undertake testing and observation for a pre-existing heart condition".
"The Duke remains comfortable and is responding to treatment but is expected to remain in hospital until at least the end of the week," the palace said.
Philip – the longest-serving royal consort in British history – was first admitted to King Edward VII hospital on February 16 as a "precautionary measure", making his time there his longest hospital stay to date. He will turn 100 on June 10.
The Duke is no stranger to being hospitalised, having received treatment for various health conditions over the years, including a blocked coronary artery in 2011, a bladder infection in 2012 and exploratory surgery on his abdomen in 2013.
Following a two-night hospitalisation for an infection in 2017, he retired from public duties at the age of 96, and underwent a hip operation 12 months later. He then spent four nights at King Edward Hospital in December 2019, where he was treated for what was described as a "pre-existing condition" and was discharged on Christmas Eve that year.
But the mood inside Windsor Castle has "shifted" after today's hospital move, royal editor at The Mirror, Russell Myers, told The Today Show this morning.
"Today the mood did shift," Myers said. "Certainly the staff I spoke to at Windsor Castle said it was a definite shift in the feeling towards Prince Philip.
"The palace have not wished to give a running commentary on this.
"(But) it's a bit more serious than we were first led to believe. I think everyone has their fingers crossed for him."
He added it was important "not to prejudge the health of a 99-year-old".
"We know Prince Philip has been in hospital for two weeks. He's certainly going to stay there until the end of the week," Myers said.
"He had trouble with his heart in 2011. It seems as though he needs to stay in the hospital for them to observe his heart this time."
Veteran royal photographer Arthur Edwards told the show last week he'll only worry about the Duke's health if the Queen turns up for a visit.
The Duke's transfer comes a day after the Queen's former press secretary claimed Prince Charles had been asked to visit his father's bedside to discuss the royal family.
Dickie Arbiter, who served the Queen from 1988 to 2000, said the Duke would have "requested" his son's presence when Prince Charles visited him the weekend before last.
Arbiter told True Royalty TV's The Royal Beat that the father-son visit was likely an emotional one.
"I think it was at the request of the Duke that the Prince of Wales visited," Arbiter said.
"To lay the ground. Look, the man is 99, he is in with an infection. My guess is that he will come out, he will walk out and he will go back to Windsor.
"But eventually he is going to die and he was just saying to Charles, 'One day you are going to be the leading man of the family.'"
Prince Charles was seen leaving the hospital last weekend with tears in his eyes after spending around 30 minutes with his father.
Meanwhile, Prince Edward, the youngest child of the Queen and the Duke, told Sky News he had spoken to his father on the phone and the family were "keeping their fingers crossed".
The Earl of Wessex said the Duke was "a lot better, thank you very much indeed, and he's looking forward to getting out, which is the most positive thing. So we keep our fingers crossed".
Prince Edward said the family had received "brilliant and lovely messages" and that "we really appreciate that and so does he".