The Center School on The Upper West Side of Manhattan Avoids Diversity. Really.

School officials call it “academic diversity,” but a well-meaning plan to equalize access to good schools has sparked an ugly racial debate that pits white, affluent parents against poor blacks and Latinos.

The recently announced proposal in District 3 — which covers the West Side of Manhattan from 59th Street to 122nd Street — would give bottom-scoring elementary-school students “priority” for admission to most middle schools. The district’s schools are sharply divided along racial and socioeconomic lines.

High-performing middle schools — usually with a white, middle- or upper-class majority — would have to reserve up to 25 percent of their seats for students who score at the lowest 2 of 4 levels on state math and English tests. That means some students with high test scores would be shut out of their preferred schools and possibly steered to lower-performing schools which enroll more blacks and Hispanics.

It’s the first proposal of its kind in New York City, but the social experiment paves the way to expand to other schools and districts.

And that threatens to raise racial tensions akin to explosive school battles in Boston, Detroit and LA, said David Bloomfield, a Brooklyn College and CUNY Graduate Center education professor.

“Without strong leadership, this strategy may divide the city based on racial politics — those who favor desegregation against those who don’t,” Bloomfield said.

New York City schools are the nation’s most segregated by race and class, a 2014 UCLA study found.

The proposal would affect current 4th graders who will enter the 5th grade in September, and apply to middle school in December. The DOE hopes to approve the plan by June.

The controversy erupted at a recent community meeting, videotaped by NY1, when one mother at high-ranked PS 199 on the Upper West Side angrily asked what she should tell an 11-year-old who “worked [their] butt off” but was shut out of the best school. “Life sucks!”

Mona Davids, president of the NYC Parents Union, blasted “progressive limousine liberals” at the popular school, where 62.2 percent of kids are white and 14.9 percent are Asian.

“It’s racism because they know the students who are doing poorly and condemned to failing schools are black and Latino. They don’t want those students in their lily-white schools,” she said.

Schools Chancellor Richard Carranza, who joined the city school system this month, fanned the flames Friday by retweeting a news story on the meeting headlined: “Watch: Wealthy white Manhattan parents angrily rant against plan to bring more black kids to their schools.”

In a WNYC interview Friday, Mayor de Blasio said he did not believe that Carranza “intends to vilify anyone.”

Some parents at poor-performing schools in the district hailed the diversity plan, which still requires DOE approval.

At the struggling PS 149 Sojourner Truth in Harlem, just 8 percent of students got a 3 or 4 — passing or higher — on the state English test last year, and only 1 percent hit those scores on the math test. The school is 90 percent black and Hispanic.

Jameelah Ricks, whose son is a second-grader at the school, said low test scores don’t mean a child can’t improve.

Parents who oppose the plan stereotype low-income minorities and worry they will “flood” their elite schools, she told The Post.

“We’re all not ghetto, project, welfare recipients. I’m educated. I’m actually in my second year in law school. I’m a senior corporate paralegal,” Ricks said.

But opposing parents at high-performing schools say the plan turns the merit system on its head.

“I think it’s very crooked,” said Aya Goshen, whose son is in grade 4 at PS 199 on West 70th Street. “You tell your kid that he needs to do his best on the test to get into a good school and it turns out he’d better get a 2, and he might get into a better school. The system is motivating kids the wrong way.”

The diversity plan, if approved, will affect Goshen’s son when he applies to middle school,

“I am very worried,” she said. “Diversity is good for our kids but the environment needs to supply the kids that are struggling with tools so they won’t disturb the kids that are not. Unless they do that, the kids who have 3s and 4s are going to suffer.”

DOE officials did not address in detail how schools will handle the mix of students at sharply different academic levels, or how they will improve the poor-performing schools where many kids will still be stuck.

Enrollment in Harlem schools has dropped because of competition from charters and other district schools, said Dennis Morgan, a member of the District 3 Community Education Council.

“I’m concerned that this is going to exacerbate problems with enrollment,” he said of the diversity plan.

Admission to elementary schools is normally determined by residential zones. But after grade 5, students can apply to middle schools in their district. Students rank their preferences, and can list up to 12 choices.

Some schools also rank the students they want. Then, students are matched to schools by computer algorithms that typically give most students their first or second choice, experts said.

In another citywide change under the proposal, schools will not see how students rank them. So schools could no longer favor kids who rank them No. 1.

Currently, some popular schools cherry-pick the highest-scoring kids. In District 3, for instance, MS 54 Booker T. Washington in Morningside Heights enrolls 80 percent of students who score a 3 or 4 on the English test and 85 percent who score a 3 or 4 in math. The school is 62 percent white, 11.5 percent Asian, 12.7 percent Hispanic and 7.7 percent black.

Graduates move on to the city’s top high schools, including Bronx HS of Science and Stuyvesant HS.

Under the District 3 plan, 17 middle schools would offer up to 10 percent of seats to students who score an average 1 on their fourth-grade exams and up to 15 percent to those who score an average 2.

A suggestion to limit the percentages of kids with 3 and 4 scores at each school was nixed, for now, as “too drastic.”

Based on 1,815 applications last year, the DOE estimates that, if the diversity plan was in effect, 118 families would get into a school higher on their wish list, while 56 would get a less-desired placement — or none of their choices.

“Because there’s a fixed number of seats in the best schools, somebody has to lose,” said Aaron Pallas, an education professor at Columbia University’s Teachers College. “It’s the fear of white, middle-class parents, whose children have done well in school, that they will be losers.”

Clara Hemphill, editor of the local education site Insideschools.org, said the city should increase the number of seats at popular, high-performing schools to expand opportunities for all.

Some parents admit that privilege must not determine opportunity.

“There are some really good middle schools in New York City and it shouldn’t just be rich kids who get to go to them,” said Josh Auerbach, whose daughter is a 5th-grader at PS 199.

But he added that some parents are upset because “school integration is scary. Even when it’s the right answer, it’s scary.”

Other diversity efforts across the city are also underway.

In Brooklyn’s District 15, which takes in Park Slope, Sunset Park and Red Hook, a consultant was hired to help shape a plan for its middle schools, which have an uneven racial and economic distribution.