Chicago Mayor Richard Daley is lashing out at Gery Chico’s campaign for defending comments Daley says are anti-Semitic.

A union leader who’s supporting Chico’s bid for mayor referred to former White House Chief of Staff Rahm Emanuel as “a Wall Street Judas” who was looking for a bag of silver. The labor leader, Tom Sweeney, made the comment at a pro-Chico rally while talking about Emanuel’s support for the North American Free Trade Agreement, or NAFTA.

Emanuel, who is Jewish, stopped short of calling the comment anti-Semitic. But he said he trusts Chicagoans will reject the “ugliness behind it.”

Mayor Daley on Thursday had much stronger language for Chico’s campaign.

“I think everybody should refute it,” Daley said. “I think it’s a disgrace. I think it’s wrong for a campaign. Win on the issue, and not on the [ethnic] origin or [religion] of anyone. Do not take that point. And that lowers the campaign for the city of Chicago and it’s a disgrace.]

During the short campaign to replace him after decades in City Hall, Daley has generally refrained from making public comments about the campaign. But Thursday was at least the second time he’s publicly criticized Gery Chico, his former Chief of Staff.

Chico’s campaign didn’t immediately respond to Daley’s comments Thursday afternoon. But in an earlier statement, the campaign said the comments were not anti-Semitic, and pointed out that Chico has three Jewish children. The Chico camp defended the comment, suggesting it was meant to denote betrayal, rather than anti-semitism.