London: Britain's National Health Service is facing such a crisis this winter that when Lord Mountbatten's 88-year-old daughter was rushed to hospital by ambulance after collapsing with pneumonia, she was left waiting on a trolley for 20 hours.

Only then could a bed be found for Lady Pamela Hicks - and that too not in a normal part of the John Radcliffe Hospital in Oxford but in a neuroscience ward.

This winter, some hospitals are cancelling all routine operations to be able to cope with emergency admissions, usually of elderly patients.

The NHS, which remains Britain's pride and joy, is marking its 70th anniversary. Its principle is that treatment should be free at the point of delivery and priority determined only by medical need. But with an ageing population NHS resources are stretched to breaking point.

When Pamela was admitted in the early hours of the morning she was treated as an elderly patient - and not fast-tracked simply because she hails from one of Britain's most aristocratic families.

Lord Mountbatten, the last viceroy of India, and his wife Edwina, had two daughters, Patricia and Pamela.

Lady Pamela Hicks is the widow of interior designer David Hicks, who died in 1998.

In her youth, she was a bridesmaid when Princess Elizabeth married Pamela's cousin, Prince Philip. When Elizabeth undertook tours of the colonies, Pamela accompanied her as lady-in-waiting.

The details of what happened at the weekend were provided by her daughter India Hicks, 50, who lives and runs a lifestyle brand in the Bahamas but flew over when she learnt her mother was very ill despite suffering from flu herself.

She said: "My mother, being a lot stronger than most of us, had disguised her pneumonia much better than I had... till finally collapsing from a lack of oxygen.... Having the excitement of an ambulance rush her to hospital in the middle of the night she was then kept on a gurney for 20 hours before the NHS found her an available bed."

Anyone who has encountered Bertie Wooster's Aunt Agatha in P.G. Wodehouse will know English women of a certain class are indomitable.

Pamela said: "I arrived in A&E (accident and emergency) on a busy, busy, busy night. I stayed in hospital for about three days. I'm now recovering from pneumonia at home. The NHS were brilliant.The staff were fantastic and I had wonderful care when I was in hospital."