Mitch Winehouse has urged his daughter's fans to "pray" for her ex-husband who is fighting for his life after an apparent drink and drug binge.
Blake Fielder-Civil, 30, was found choking in bed by partner Sarah Aspin last Friday before being rushed to hospital with multiple organ failure.
Mitch said it was "terrible news", writing on Twitter: "Remember Amy loved him. Let's pray for his recovery."
Fielder-Civil, a recovering drug addict, had gone out drinking with a friend the previous day and his girlfriend, who is mother to his 15-month-old son, said she believed he might have taken an illicit substance.
He was put into an induced coma and is on a life support machine in hospital in Dewsbury, West Yorkshire.
Aspin, 34, who met Blake in rehab three years ago, told The Sun: "The doctors said they put him in a coma to help him and due to infection. I'm praying he'll survive, but I'm having to prepare myself that he may never wake up."
She said Blake attended an appointment with the Probation Service in Morley and then met a friend the day before he was rushed to hospital. He returned home slurring his words and staggering before being put to bed.
The next morning she woke to find him unconscious before paramedics confirmed he had swallowed his tongue and choked on his vomit.
Blake, who married pop star Winehouse in 2007 before the pair divorced two years later, has long battled heroin addiction and spent time in prison in 2007.
He was jailed again in June last year for burglary and possession of an imitation firearm before being freed with a tag two weeks ago in preparation for his full release.