The Duke of Edinburgh is expected to remain in hospital for a third night following his admittance on Tuesday after feeling unwell at Windsor Castle. Prince Philip was taken to the King Edward VII’s hospital in central London as a “precautionary measure”. Sources said it was not Covid related. There were no reports of any visitors arriving at the private hospital on Thursday. Buckingham Palace previously said he was expected to remain “for a few days of observation and rest”. No update on his condition has been given. Philip, who will celebrate his 100th birthday on 10 June, was a non-emergency admission, travelling to the hospital by car, and was said to have been in good spirits and to have walked into the hospital unaided. He and the Queen, who have spent the pandemic together at Windsor Castle, both received their Covid-19 jabs in January. He spent four nights in the same hospital in December 2019, where he was treated for a “pre-existing condition” and discharged on Christmas Eve. Boris Johnson, the prime minister, is among those to have sent their best wishes for his recovery. The Queen has remained at Windsor Castle. Buckingham Palace said in a statement issued on Wednesday: “His Royal Highness the Duke of Edinburgh was admitted to King Edward VII’s hospital in London on Tuesday evening. “The duke’s admission is a precautionary measure, on the advice of His Royal Highness’s doctor, after feeling unwell. “The duke is expected to remain in hospital for a few days of observation and rest.”