The queen received the new British Prime Minister, Liz Truss, at Balmoral on Monday / REUTERS

Senior members of the Royal Family rush to be at the side of Queen Elizabeth II in Scotland

The queen's four children travelled to the Balmoral estate after Buckingham Palace released a statement earlier today saying that doctors were "concerned" about the state of the health of the 96-year-old monarch

ÍÑIGO GURRUCHAGA London

Queen Elizabeth II is under constant "medical supervision" after her doctors expressed their "concern" this Thursday, 8 September, about the state of health of the monarch.

Her Majesty, 96 years old, is still at the Balmoral Castle estate, in Scotland, where the UK’s new prime minister, Liz Truss, was officially installed on Monday because the monarch could not travel to the traditional setting of Buckingham Palace due to mobility issues.

"Following further assessment this morning, the Queen's doctors are concerned for Her Majesty's health and have recommended that she remain under medical supervision. The queen is still comfortable and at Balmoral,” said the brief statement from Buckingham Palace.

Minutes later, the new prime minister, Liz Truss, stressed that "the whole country is deeply concerned about the news from Buckingham Palace." "My thoughts and those of people across the UK are with Her Majesty the Queen and her family at this time," she stressed.

The queen's four children, Prince Charles of Wales, Princess Anne; Prince Edward, Earl of Wessex; and Prince Andrew, Duke of York, have travelled to the Balmoral estate to be at the side of their mother. Prince William, Duke of Cambridge and grandson of the monarch, and the Duchess of Cornwall, Camilla Parker Bowles, have also attended. They will also be joined by Prince Harry, grandson of Elizabeth II, who is travelling to Scotland without his wife Meghan Markle.

Gibraltar's chief minister, Fabian Picardo, has this afternoon tweeted, "The thoughts of the loyal people of Gibraltar are with Her Majesty the Queen at this time. We wish her well and will all hope and pray for her speedy recovery."