Last December Winnie Johnson, 78, said she hoped to come face-to-face with her son's killer after a judge ruled Brady's mental health tribunal would be held in public.
However, her solicitor John Ainley, Senior Partner at North Ainley Halliwell, said yesterday that Mrs Johnson was currently in hospital and not well enough to attend.
He said: "In any event, it would be too traumatic for her to have any involvement in a hearing that deals with Ian Brady.
"Winnie has made it perfectly clear that she considers Ian Brady should remain in a mental hospital for the remainder of his life and not be transferred to a prison either in England or Scotland.
"Presumably, the intention would be to go on hunger strike with a view to ending his own life. She does not consider this should be his prerogative."
Brady, who was born in Glasgow, wants to be transferred to a Scottish prison and be allowed to die.
The hearing, to be held on July 9, will be a rare chance to see the Moors Murderer in public.