Earlier this week 67-year-old cancer patient Jill Baker complained after finding "not for resuscitation" written on her medical notes.

Age Concern says the publicity surrounding the case has sparked thousands of calls from people who say they or their relatives suffered age discrimination in the NHS.

Another 40 "not for resuscitation" cases have been unearthed.

Mrs Baker's case triggered an inquiry by the Department of Health, which said her treatment was in breach of the British Medical Association's own guidelines for doctors.

A spokeswoman for the charity said: "We are in the middle of a campaign against age discrimination in the health service and had in the last six months unearthed 10 cases where orders had been given by doctors not to resuscitate patients without their consent.

'Lines jammed'

"In addition we had half a dozen more people who had been casually asked about resuscitation as soon as they came into hospital with no clinical diagnosis."

She said: "Jill Baker's case, at St Mary's Hospital, Portsmouth, last week prompted thousands rather than the usual hundreds of calls to our information lines which were jammed.