Sir Terry Pratchett is offering himself as a test case for assisted suicide "tribunals" to give people legal permission to end their life with medical help.
The author, who has Alzheimer's disease, will say that the "time is really coming" for assisted death to be legalised as he delivers the Richard Dimbleby Lecture tonight.
He wants to see a tribunal set up to which people with incurable diseases can apply for assistance. A legal expert and a doctor who had dealt with serious, long-term illness would be part of the body, he will add. "If I knew that I could die, I would live. My life, my death, my choice," he will say.
The comments come days after Kay Gilderdale was acquitted of attempted murder after helping her daughter Lynn, who was paralysed by ME, to end her life. A poll of 1,010 adults for tonight's Panorama on BBC One found 73 per cent backed legalisation of assisted suicide for the terminally ill.