The patients’ rights campaigner Claire Rayner, who died on Monday, told her relatives she wanted her last words to be: “Tell David Cameron that if he screws up my beloved NHS I’ll come back and bloody haunt him.”

The former president of the Patients Association never recovered from emergency intestinal surgery she had in May this year and died in hospital near her home in Harrow, north-west London.

Rayner started her career in the National Health Service working as a nurse.

Des Rayner, her husband of 53 years, said: ”Through her work she helped hundreds of thousands of people and doubtless, by talking frankly about the importance of safe sex in the 80s when almost nobody else would discuss it, helped to save thousands of lives.

“Through her own approach to life she enabled people to talk about their problems in a way that was unique.

“Right up until her death she was being consulted by both politicians and the medical profession about the best way to provide the health services the nation deserved and nothing mattered to her more than that. Her death leaves a vacancy which will not be filled.”

Katherine Murphy, association chief executive, said: “I would like to join with everyone involved in the Patients Association in expressing my deep sadness at the death of our much loved president, Claire Rayner.

“For almost 30 years Claire has devoted so much of her time and energy to championing patients’ issues. She was a figurehead and inspiration to us all.

“She cared so deeply that the voice of the patient should be heard and worked tirelessly to ensure that care issue were given prominence in all health matters. She was a wonderful person, an inspiration to us all and she will be missed so much by everyone.”