"I think it's wrong for a campaign. Win on the issues, and not on the ethnic origin or religious [background] of anyone. Do not take that point. And that lowers the campaign for the city of Chicago and it's a disgrace," he said during a question-and-answer session at City Hall.
He called on Gery Chico to publicly condemn and reject the comments.
During a fiery speech introducing Chico at a fundraising event on Tuesday, the president of the International Union of Operating Engineers Local 150, Jim Sweeney, called Emanuel "nothing but a Wall Street Judas."
Sweeney said the remark was in reference to Judas being a traitor, but Emanuel was offended and his campaign said the remark had religious undertones.
"My brother was on Wall Street. They didn't condemn him, did they?"