A former professor has sued Pace University for discrimination, claiming observant Jewish and older teachers were pushed out of the math department when it came under new leadership, according to the new lawsuit.

Jonathan Gersch — who is Jewish and wore a yarmulke to school — says he worked as an adjunct math and statistics professor at Pace for more than 15 years. Then, starting in 2016, the new department chair, Professor Shing So, started cleaning house to bring in younger and cheaper staff, the new Manhattan Supreme Court lawsuit filed late Wednesday charges.

Gersch’s suit claims that soon after 2016, all of the “observant Jews” and 50 percent of the 15-year-plus employees were let go.

“While observant Jews were under 8 percent of the 51 adjuncts, ALL of them — 100 percent — were pushed out after the 2016 academic year,” the suit claims.

Gersch said “there had been friction” between him and the university “regarding making reasonable accommodations for Jewish holidays in the past,” the court papers say.

He says he was forced out under false pretenses after the university did not renew his adjunct position in March 2017.

“Gersch believes that he was wrongly discharged based on his religious identity as an observant Jew,” the court papers allege.

The Manhattan man — who filed a similar suit in February, which is still pending — is suing for more than $500,000.

“Pace has a zero tolerance policy against discrimination in the workplace. Under the university’s policies, if we receive a complaint, we investigate thoroughly and take appropriate action,” said Marie Boster, a Pace spokesperson.

So — who is not named as a defendant in the suit — did not immediately return an email request for comment.