The ever-popular singing star is critically ill, having contracted pneumonia following a bone marrow transplant.
Family and friends are at his bedside in the intensive care unit of Manchester Royal Infirmary where he underwent life-saving treatment in his long battle with cancer.
Tour manager, Zeb White, said reports Joe had slipped into a coma were untrue, although the 50-year-old is desperately ill.
He said: "Joe caught a chest infection after a line was inserted into his chest in order to administer drugs, but this was rejected by Joe as he has no immune system.
"Doctors on the ward decided to sedate Joe and put him on to a ventilator, so now he is in deep sedation and is critical – ut is being able to take the drugs.
"A few days ago he was very bad and his body was rejecting everything. He is still very ill, but Joe has the constitution of an ox and I'm sure he will pull through."
Former Grumbleweed and close friend, Tony Jo, said the next 10 days were crucial, but he was confident he would pull through.
He added: "Doctors have told us that this is normal after a patient has undergone a major operation.
Joe has been battling non-Hodgkin's lymphoma since 1988 and has been sent hundreds of cards from well wishers. His website has also been inundated with get well messages from concerned fans.
He bowed out of public life last year, but has made a few emotional appearances in front of thousands of Blackpool fans in the past six months.
But doctors forced the veteran singer to pull out of a summer season show at Blackpool's Paradise Rooms due to the cancer.
Tony Jo added: "He is in good spirits and if anyone can get through this then it's our Joe."
"The good news is that the bone marrow has started to produce cells which are working, but these things are like car engines – sometimes they work and sometimes they don't.
"The next 10 days will be crucial to Joe in whether he can pull through this, but I and his family are certain that he can battle this as he has done with everything else.
"I would ask his army of fans who are reading this to light a candle for our Joe as he needs all the support he can get over the next week or so."
Pat Mancini, a close friend of Joe, said: "He is still critically ill, but doctors are more pleased with his progress today than they have been for the last week.
"He has had a better night last night and we are hoping and praying that he will pull though."