Williams believes Babyshambles frontman Doherty, who has had a well-publicised battle with drugs and is the on/off boyfriend of catwalk queen Kate Moss, cannot continue living the way he has been, no matter how "pretty" his existence might seem from the outside.
FEEL star Williams, who once battled a drug habit himself, says, "Addiction is different with Pete Doherty. He's different and we live in very different times. It isn't the 1960s anymore. People don't have to die because of their addictions - they get clean.
"It's not as if people haven't reached out to Pete.
"And I'm not being funny, but there's a sense of his addiction being quite pretty. You know? He stays up all night off his head and then the next day at midday he goes down to the beach with a supermodel wearing a silver ball gown to shoot tin cans off a wall. It's appealing.
"My addiction did not look like that. I'd end up with any old idiot who'd talk s**t with me till the early hours. That wasn't pretty."