Mayoral candidate George Smitherman has been accused of swearing at a volunteer for rival Rocco Rossi's campaign during what he calls a rude confrontation on Thursday night.

The mayoral debate at University of Toronto's Hart House took a controversial turn on Thursday night before the candidates even took the podium. According to reports, a young volunteer for Rossi's campaign attempted to give Smitherman campaign material as he entered the debate. She claims he then swore at her.

According to Smitherman, the volunteer had no visible campaign identification and was trying to hand him "misinformation" that wasn't clearly affiliated with any candidate.

"You come onto me rudely, I'm going to come right back at you rudely." he told CTV afterwards, adding "the way she confronted me warranted a similar response."

Rossi called Smitherman's behaviour "completely unacceptable" and told CTV "I think that young woman is owed an apology."

In a statement released Friday, Rossi's campaign called on Smitherman to immediately apologize to the young woman.

Thursday night's Youth Priority Symposium Debate was hosted by the Creative Institute for Toronto's Youth Leaders.