New York City Schools Chancellor Richard Carranza is a thin-skinned divider obsessed with “ethnicity rather than efficacy,” charges a nine-member, bipartisan coalition of city and state pols who on Saturday demanded the mayor fire him if his “contentious rhetoric” continues.

“We need a chancellor who promotes education, not division,” declares the damning dispatch, obtained by The Post, to Mayor de Blasio, “If Chancellor Carranza continues to divide this city, then someone who can unite this city and provide a quality education for all should replace him.”

The letter was written by Queens Councilmember Robert Holden, a Democrat, and signed by eight others, including two Republican members of the Council’s Education Committee, Joseph Borelli of Staten Island and Eric Ulrich of Queens.

“Since coming to New York in April 2018, Carranza has rightfully focused on creating a more equitable school system, but his comments and actions have seemingly made the system even more divided. He has yet to outline a comprehensive academic agenda.”

It adds, “Rather than taking criticism into honest consideration, Chancellor Carranza and his administration respond by making accusations of their own.”

Last week, Carranza railed that he’s been blasted over his hiring practices because he is “a man an of color.”

“There are forces in this city that want me to be the good minority and be quiet,” he said. “I will not be silenced.”

Meanwhile, the coalition cites a “deep concern” over a lawsuit by three white veteran DOE administrators charging that Carranza has fostered a “hostile atmosphere.” As first reported by The Post, the plaintiffs, all women, claim they were demoted or pushed aside for less qualified people of color.

The letter lists allegations that have “resulted in alienating key stakeholders” in city schools.

“Cronyism in the hiring process.” Carranza has given jobs to people he met while leading school districts in San Francisco and Houston, some without New York certification or job postings.

“Usurping trusted job candidate search committees.” Carranza hired a man he knew in California as a $205,416-a year “senior executive for continuous school improvement” without advertising the opening.

“Meritless firing or demotion of qualified, veteran employees.” The women who filed the lawsuit contend they were stripped of duties despite excellent track records.

“Releasing divisive statements directed toward parents and students.” Carranza has suggested that white parents who dislike his remarks or proposals need implicit-bias training.

“Changing policies based on ethnicity rather than efficacy.” Carranza wants to eliminate the entrance test to eight specialized high schools because current enrollment of black and Hispanic kids totals 10 percent, while Asians and whites make up 70 percent. “I just don’t buy into the narrative that any one ethnic group owns admission to these schools,” he declared in June 2018.

“Creating an environment for schools to potentially violate equal employment opportunity laws.” The Post reported that Community School District 1 in Manhattan advertised for “teachers of color.” The ad invited candidates to the district’s first “Job Fair for Diverse Teachers.” The DOE yanked the illegal ad, and insisted the fair was open to all.

Besides Holden, Borelli and Ulrich, the other councilmembers who signed the letter are Democrats Peter Koo, Karen Koslowitz, Paul Vallone and Chaim Deutsch. Assemblymen Peter Abbate, Jr. and William Colton, both Democrats, also signed.

A spokeswoman for the mayor ripped the coalition.

“It’s a sad day for New York City kids when lawmakers care more about seeing their name in the NY Post than about our school system,” Freddi Goldstein said.

“This racially charged smear campaign is the only thing dividing our city and anyone backing it should be ashamed. We stand with Chancellor Carranza and thank him for all he’s doing to bring equity and excellence to all our kids.”