Piers Morgan says he 'can't even imagine' Britain without The Queen.
The former Good Morning Britain host took to Twitter after news broke that "doctors are concerned for Her Majesty's health".
"I can't even imagine Britain without this Queen. Very unsettling day," he said.
He, along with other celebrities, have met HM The Queen on several occasions and only recently released a special item on his TalkTV show called 'It's time to celebrate The Queen'.
Prince Charles, Camilla and Prince William have rushed to Balmoral to be by her side while other members of the royal family have been informed this afternoon.
It follows months of concern for the 96-year-old's health which has seen her pull out of several official and private engagements.
Prince Harry and Meghan Markle are also on their way to Balmoral Castle following the rare announcement from Buckingham Palace officials.
The Royal 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.
"The Queen remains comfortable and at Balmoral."
Following the news, Prime Minister Liz Truss tweeted: "The whole country will be deeply concerned by the news from Buckingham Palace this lunchtime.
"My thoughts - and the thoughts of people across our United Kingdom - are with Her Majesty The Queen and her family at this time."
The leader of the Labour Party tweeted: "Along with the rest of the country, I am deeply worried by the news from Buckingham Palace this afternoon.
"My thoughts are with Her Majesty The Queen and her family at this time, and I join everyone across the United Kingdom in hoping for her recovery."
The BBC has cleared its scheduled programming following today's announcement. It cut its midday show short for a BBC News special.
The broadcast was interrupted during Bargain Hunt, as a BBC newsreader confirmed: "Welcome to viewers on BBC One. We have had news from Buckingham Palace that the Queen is under medical supervision at Balmoral."
She then detailed concern for the Monarch's health, and the news remained on air instead of returning to usual programming.
