The 91-year-old Duke, who was on Thursday presented by the Queen with the Order of New Zealand – that country’s highest honour – had also attended a garden party at Buckingham palace, where he chatted with guests.
It now seems likely that he will spend his 92nd birthday next week in hospital.
Speaking after the Duke cancelled an engagement the night before the service to mark the 60th anniversary of the coronation, the royal couple’s eldest grandson Peter Philips told ITV Daybreak:
“they do a lot a lot more than most other pensioners of their equivalent age. So if occasionally there is the odd engagement cancelled it shouldn’t come as a surprise given the work load they do have.”
However, Prince Philip was back at the Queen’s side the following day for the commemoration at Westminster Abbey.
The Duke has experienced several bouts of ill health recently, spending Christmas 2011 in hospital with a heart condition and attending hospital for bladder infections twice in the last eight months.
The Duke had been due to accompany the Queen on a visit to open the BBC’s newly refurbished Broadcasting House on Friday.
The Prime Minister wishes the Duke of Edinburgh a swift recovery