The Duke of Edinburgh was flown to hospital yesterday amid growing fears for his health.
Buckingham Palace stressed last night that he was not an emergency case and was being treated for a ‘pre-existing condition’.
But the Mail can reveal that Philip, 98, was flown by helicopter from the Queen’s Sandringham Estate in Norfolk to London before being driven to the King Edward VII Hospital in Marylebone.
Prince Philip, pictured here in February 2018, was flown to London from his home in Sandringham for hospital treatment for a pre-existing condition, Buckingham Palace has announced
The Duke of Edinburgh has been admitted to King Edward VII hospital in Marylebone, London

The Queen, pictured centre left, started her official Christmas holiday yesterday arriving at Kings Lynn station on the Royal Train, shortly before her husband was airlifted to hospital
The dash came as his wife left Buckingham Palace for Sandringham, where she hopes he can still join her for Christmas.
Sources confirmed that the duke has not been in the best of health in recent weeks as he battles a flu-like condition.
Philip has lived alone in a farmhouse at Sandringham since his retirement from public life in 2017. He is said by royal insiders to be increasingly frail.
‘The duke has had a bad turn recently and has been looking much frailer of late,’ one said. ‘He’s a remarkable man who has always prided himself on how robust he is, but he is six months off his 99th birthday and age takes its toll. He hasn’t been looking terribly well of late.’
In a statement issued yesterday afternoon, Buckingham Palace insisted that the duke’s hospital stay had been planned.

Royal sources insisted that Prince Philip is expected to return to Sandringham in time for Christmas after being flown to London for hospital treatment
It said: ‘The Duke of Edinburgh travelled from Norfolk this morning to the King Edward VII Hospital in London for observation and treatment in relation to a pre-existing condition. The admission is a precautionary measure, on the advice of His Royal Highness’s doctor.’
It is understood Philip was not taken by ambulance and was able to walk into the hospital unaided.
The royal is expected to be in hospital for a ‘few’ days, but the Palace was unable to confirm whether he would be released in time for Christmas.
Officials declined to comment when asked to confirm that he had been brought to London by helicopter, or to share further details of his health.
Last night the only sign of his presence at the King Edward VII Hospital was several police officers guarding the main entrance.
Philip flew the 120 miles from Norfolk to London as his wife left Buckingham Palace planning to join him in Sandringham for their annual Christmas break. Looking radiant in a pink coat, pearls and light blue headscarf with a sweep of fuchsia lipstick, the 93-year-old monarch was driven on to the platform at King’s Cross station in London by her official Bentley to catch the 10.42am Great Northern train to King’s Lynn in a rare concession to her age.

Prince Philip, pictured in Balmoral, is expected to spend a few days in hospital before being discharged and returning to Sandringham to his family
She could be seen smiling through the train window and arrived in Norfolk at 12.31pm.
After descending carefully on to the platform, she was driven the last ten miles to her estate.
Palace sources suggested that the Queen was sufficiently relaxed about her husband’s health to still make the journey.
But the monarch is also a stickler for tradition who hates letting people down, and would likely have made the journey anyway. She also rarely visits even her closest relatives in hospital.
It is not known whether Philip will receive any other visitors during his stay and it is likely to depend on how his treatment progresses over the weekend.
But the proud duke will also no doubt be keen to have the minimum of fuss and it is understood that other members of the Royal Family, including the Prince of Wales, who has engagements on Monday visiting victims of the floods in Fishlake, South Yorkshire, are not cancelling their existing plans just yet.
The duke, who will celebrate his 99th birthday next June, has enjoyed largely excellent health for most of his life, appearing to recover well from a planned hip replacement in April last year.
He even escaped with minor injuries after a car crash near Sandringham in January, which led him to voluntarily give up his licence, but was said to have been left deeply shaken by the incident.
But over the past decade he has been admitted to hospital for abdominal surgery, bladder infections and a blocked coronary artery, which also saw him flown to hospital by helicopter.
The duke has rarely been seen since his retirement from public duties, apart from at the odd family engagement.
He was last spotted over the summer, enjoying the Royal Family’s annual sojourn at Balmoral.