Gascoigne, 45, who has spoken about alcoholism problems in the past and was sectioned five years ago under the Mental Health Act, appeared to be unwell and trembling at a charity appearance in Northampton on Thursday.
The former Tottenham, Rangers and Lazio star told guests at the £100-a-head bash: "I’m sorry. Three days on the whisky..."
His agent Terry Baker told BBC Radio Five: "He won't thank me for saying but he needs to immediately get help.
"Whatever's happened to him in the five or six weeks since I saw him before Christmas, he is not as well as he has been.
"He's been absolutely fine, he really has, and now he isn't. But I think he knows that."
He went on: "His life is always in danger because he is an alcoholic. Maybe no-one can save him - I don't know. I really don't know."
The Mirror ran a front page story on Gascoigne's condition on Sunday and said that he is "hooked on a mix of valium and strong lager."
The paper carried a picture of Gascoigne buying alcohol at 11am on Saturday morning.
The Mirror claims that Gazza has told friends: "The one thing I can't live without in my life is a drink. I know I have to stop boozing but I simply can’t."
His former club and international team-mate Chris Waddle told the paper: "We’ve just got to hope that one day the penny will drop and he’ll get through all this. I wish him all the best and hope he can be a bit stronger.
"What he really needs to know is that he’s loved by everybody in England and the whole nation will be rooting for him."
Gascogine played 57 times for England between 1988 and 1998 scoring 10 goals for the national team.