Mayor Bloomberg unexpectedly halted legislation aimed at cab drivers who participate in sex trafficking Wednesday.

Bloomberg surprised City Council members at a bill-signing ceremony by putting off a decision on the measure.

The mayor responded to complaints that drivers could be forced to determine whether a passenger was a prostitute.

"I do worry that if my daughters are out there after they are at, you know, a club and they come out late at night and they’re dressed a lot more risqué-ly, if that’s a word, than people my generation did, but still appropriate for their generation, it does put a taxi driver in a difficult position,” the mayor said.

City Council Speaker Christine Quinn responded by saying the mayor's words demonstrate a fundamental misunderstanding of the bill.

"Who wants someone who is a sex trafficker, convicted, to have the privilege of driving New Yorkers around?" she said. "I don't. When the mayor learns the facts he won't either."

Quinn said the bill applies only to convicted sex traffickers and specifies that drivers cannot refuse passengers based on appearance.