City Councilman Fernando Cabrera speaks at a press conference defending teachers outside City Hall today.

The best antidote to teacher-bashing, according to City Councilman Fernando Cabrera, is being a teacher.

At a press conference today to criticize the release of teachers’ ratings and the tone Mayor Bloomberg has set recently when talking about city teachers, Cabrera suggested that Bloomberg take over a classroom for a week.

“I guarantee he’ll get his attitude well changed,” said Cabrera, who said his son is studying to become a special education teacher but fears that the city’s administration “doesn’t believe in teachers.”

Cabrera was unusual in suggesting that anything could be done to alter the mayor’s attitude. Steven Levin, the Brooklyn councilman who organized the event, said council members would support and honor teachers but suggested that the real change would come later — perhaps after Bloomberg leaves office in 2013.

“Hold on. Hold on, because we’ve got your back,” Levin said. “We’ll see this through — but you’ve just got to hold on.”

Levin was joined by nearly a dozen members of the council’s progressive caucus, Comptroller John Liu, several teachers, and UFT President Michael Mulgrew, who said, “The teachers of New York are feeling the love, and this is what they should be feeling.”

Dominic Recchia, a council member from Brooklyn who does not typically align himself with the progressive members, also spoke, saying his phone had been ringing nonstop with teachers who disputed their city ratings, which were based completely on student test scores.

“The best evaluation is to go into a classroom and see what the teacher is doing day in and day out,” he said.

The ratings’ release two weeks ago ignited fierce debate about whether personnel evaluations should be made public — and generated near-perfect consensus that they should not be. Bloomberg himself has been a lone defender of the release, a position he reiterated on Wednesday when signing into law a City Council bill that requires more city data to be made public.

Levin and several other council members who appeared at the press conference today had sponsored that bill. But Levin told me today that the goal of government transparency is not to bring the personal lives of city workers into public debate and that he thought teacher ratings of the type the city generated would not fall under the law’s requirements.

“What we’ve seen here is not a question of government data. It’s a question of erroneous data — bad data being used as a political weapon,” he said.

But Levin said he could imagine ratings based on a system that the city and teachers union mutually accept being fair game for release. “If you have a fair evaluation system that everyone has agreed on and can be appealed, then it’s a discussion you can have,” he said.