Footballing legend George Best is said to be close to death and is no longer receiving treatment to keep him alive.
Best, 59, developed internal bleeding on Wednesday night but had been "hanging on, proving he is a true fighter" since then, the doctor said.
The ex-Manchester United star's entire family are at his bedside, he added.
Best has been visited by relatives and friends at London's Cromwell Hospital, where he has spent the last eight weeks and been treated for a lung infection.
On Thursday, the consultant overseeing his treatment, Professor Roger Williams, said there had been "no change, just deterioration" in Best's condition and he expected him to die before Friday lunchtime.
When Best's closest family arrived at the west London hospital, they asked the gathered media not to film or photograph them as they went in.
The former Northern Ireland international has been in hospital for eight weeks, after initially suffering flu-like symptoms, but deteriorated with a lung infection a week ago.
Professor Williams said on Thursday: "Mr Best is coming to the end of the long road of his ill health.
"The situation is that medically the intensive care team and everybody concerned have managed to cope with pretty well all of the complications except the one that has happened again during the night - this bleeding.
"Although [the blood] has been replaced, it has now affected the lungs and other parts, and there is really no return from that situation.
"It is just not possible to recover from that."
Family vigil
Professor Williams said: "We have just all been sitting down together and it's very upsetting for everybody, isn't it - those looking after him, the family.
"I have talked to them at great length, I think they understand everything... I think they accept what's going to happen."
Portsmouth Football Club chairman Milan Mandaric, a close friend of Best, said: "It's not easy for them - Calum [Best's son] loves his Dad; they are all good people like George."
After visiting Best in hospital, Mr Mandaric told reporters: "What is a shame is that people who don't know George don't know what a great man he is. He's got a large heart.
"I just want George to still be around, that would be my hope."
Former team mates Sir Bobby Charlton and Denis Law also arrived at the hospital on Thursday.
Deterioration
Best was admitted to hospital on 1 October with flu-like symptoms, and suffered a kidney infection and internal bleeding before the latest decline.
Drugs needed after his liver transplant in 2002 had made the recovering alcoholic more susceptible to infection.
Things had looked more positive earlier in the week when Best was taken off sedation and regained consciousness.
But then his condition deteriorated once more between 0100 and 0200 GMT on Wednesday.
Best helped Manchester United win the European Cup in 1968 - the first English club to do so - and he was European Footballer of the Year that same year.
His style captivated football fans around the world but his playboy lifestyle degenerated into alcoholism and bankruptcy.
http://news.bbc.co.uk/2/hi/uk_news/4465456.stm