Schools Chancellor Joel Klein accused Mayor Bloomberg’s political opponents Monday of trying to politicize education. Yesterday, the Democrats struck back.

“The mayor and the chancellor wanted the responsibility and claimed they wanted the accountability,” one of the mayor’s opponents, Rep. Anthony Weiner, told The New York Sun. “Now they’re being held accountable, and the chancellor is squealing like a pig.”

Mr. Weiner was not the only Democrat to compare the schools chancellor to a quadruped, and he wasn’t the only mayoral hopeful to pounce on Mr. Klein.

“It’s unfortunate that the chancellor would choose to play a partisan role in the mayor’s re-election effort when he should be focused on what Gifford Miller is focused on, which is educating our children,” Stephen Sigmund, a spokesman for the City Council speaker, said.

“If education is being politicized,” Mr. Sigmund said, “it’s being politicized by the chancellor.”

A spokesman for Fernando Ferrer, another Democratic mayoral contender, also accused the chancellor of playing partisan politics.

“It looks a lot like Mayor Bloomberg is using his school chancellor to launch dishonest political attacks,” the spokesman, Chad Clanton, told the Sun.

A veteran political consultant, Hank Sheinkopf, said Mr. Klein’s remarks and the subsequent explosion are proof that campaign season is heating up.

“It’s all politics,” he said. “Schools have always been political in New York City. … You can’t attack the police because crime is down, so schools are the next best choice.”

The conflict erupted Monday evening, when the host of NY1’s “Road to City Hall,” Dominic Carter, asked Mr. Klein to comment on complaints by Democrats about a cut from the Department of Education’s capital budget.

“Why cut $1.3 billion from the school construction budget?” Mr. Carter asked. “The mayor has said it’s only postponing the figures, but the Democrats, including Mr. Miller and the others, say it’s a cut.”

Mr. Klein said the Democrats are “just demagoguing it.” He explained that the city administration approved the capital plan on the condition that Albany lawmakers would chip in part of the money – which they have yet to do.

Then, without any further question from the interviewer, Mr. Klein went on the offensive against Mr. Weiner, who represents a district that straddles the Brooklyn-Queens border.

“He doesn’t know what he’s talking about, but he’s going on and on,” Mr. Klein said, explaining that when Mr. Weiner recently appeared on the same program, he said the principal-training academy the Bloomberg administration founded was financed by taxpayers, though actually it is an independent nonprofit corporation financed by private contributions.

Yesterday, when the Sun asked Mr. Weiner about the academy, he said he stood by his critique.

“The idea that these funds have been raised privately, therefore the administration should not be held accountable, or that it’s okay that the money is wasted on the mayor’s pet projects, should be of concern,” the Democrat said. “If the dollars aren’t going to the classrooms, we should seriously question whether they’re being well spent.”

When Mr. Klein finished slamming Mr. Weiner, Mr. Carter asked, “What about Ferrer?”

That drew another critique from Mr. Klein. He said: “Mr. Ferrer, as far as I can tell, hasn’t said anything about education, but my sense is that what’s going to happen now is, people are going to try to politicize an issue, that, you know, Mr. Ferrer was in office for many, many years. Right? What did he do? What happened to those kids then?”

A political consultant who represents the state Democratic Party, Howard Wolfson, said Mr. Klein should stop being “the mayor’s attack dog.”

“He proactively brought up one of the mayor’s opponents for criticism. I don’t think that’s what New Yorkers expect our schools chancellor to be doing,” Mr. Wolfson said. “He should focus on fixing the schools. That seems to be a job he’s having a hard enough time with.”

He continued: “If the mayor wants to criticize his political opponents, he’s well within his rights to do that. I do not think someone who is being paid by the taxpayers to work for our children ought to be engaging in that kind of behavior.”

Mr. Sheinkopf argued that Mr. Klein is just doing his job.

“The politicians’ job is to say the schools aren’t working. The chancellor’s job is to say the schools are working,” he said. “I think the chancellor is defending his turf, which would be smart, and bringing it back to nonpolitics.”

The chancellor’s press secretary, Jerry Russo, said of the Democrats: “It’s hard to believe they would do a better job when they don’t even have their facts right.”