"You know, being a folk hero and being a good mayor are two very separate things," Vaughan, one of Ford's most vocal critics on council, told reporters on Monday.
"He may be popular as in being a folk hero. But I don't think he's going to get re-elected."
Vaughan was speaking during a break in a meeting of the mayor's executive committee, in which his motion to put in place a ban on the sale of bullets in Toronto was deferred indefinitely, essentially killing it.
"Right now, just about anybody running beats him one on one," Vaughan said, referring to a string of public opinion polls in recent months. "In fact, I haven't seen a candidate yet not beat him one on one."
Vaughan dodged questions about his own mayoral ambitions, only saying "somebody will" run against Ford.
'I've got work to do'
Vaughan also took a jab at the mayor for declaring at his family's annual "Ford Fest" barbecue on Friday that his campaign for the next election had started that day.
"I've got work to do in the ward and I've got work to do in city hall," Vaughan said.
"The mayor may have started his re-election campaign for the 15th time on the weekend. I'm still here working. We've got two and a half years left on this mandate. We have a lot of work to do before we start talking about the next election."
When asked then if it is still too early to write off the mayor, Vaughan said: "Usually it would be. Not in the case of this mayor."
Meanwhile, Ford also addressed reporters Monday, and said that the weekend barbecue was "a very humbling experience."
"There was a lot of new faces and lot of people who came up to me and said, 'You know, I didn't support you before, but I'm supporting you now,'" Ford said.
The mayor also reiterated he wants to make cuts to senior staff in an attempt to bring down costs for the 2013 budget and he supports TTC Chair Karen Stintz's push to contract out some TTC cleaning jobs.