Charter school night at the Brooklyn Museum of Art tonight became a scene of debate between two mayoral candidates, Congressman Anthony Weiner and Mayor Bloomberg — even though Bloomberg was not there.

Hundreds of parents attended the event — others were turned away at the door — which included a dinner followed by pro-charter school speakers, including Weiner and Schools Chancellor Joel Klein. Weiner implored parents to stand with him — literally, in a protest outside City Hall — in opposition to Mayor Bloomberg’s push to extend term limits.

“I have something I need you to do Monday at 9:30,” Weiner said, asking parents to join the protest that will coincide with Bloomberg’s signing of a new law allowing lawmakers, and himself, to serve three terms.

Weiner suggested that Bloomberg, by bypassing voters and ramming through a term extension, will give ammunition to opponents of mayoral control of the public schools. The law granting control to the mayor was created in 2002 but will expire in 2009 if state lawmakers do not vote to keep it on the books. Already many lawmakers are saying they intend to slash power from the mayor, who they say has acted imperiously, ignoring parental and community input as he runs the schools.

“Too often parents have been cut out of the process,” Weiner said. “Too often the community hasn’t been listened to.” Weiner supports mayoral control, and he said a term limit extension will make control harder to preserve.

Mayor Bloomberg did not attend the event, but his schools chancellor, Joel Klein, brought fighting words.

Speaking in a scratchy voice because of what he said is a case of laryngitis, Klein said that charter schools would not have been expanded over the last six years had Bloomberg not supported them, against the wishes of “entrenched interests.” (Teachers unions have lobbied lawmakers to oppose the expansion of charter schools in New York.)

Klein asked the audience to join him in continuing to battle those interests, whose identities he did not specify. “They could undo this in a second,” Klein said. “If we don’t fight, make no mistake about it, people will roll it back.”

“Get ready to fight in the school wars,” he added later. “I need you to say that you will be warriors for our kids.”