In a fiery, off-the-cuff speech delivered to supporters on Tuesday, outspoken Boys and Girls High School Principal Bernard Gassaway reiterated charges he has leveled for years: The city is keeping him from turning around his long-struggling school.

Just that afternoon, he recounted, he confronted and sent away an unwanted teacher assigned to him by the Department of Education.

“They sent a nut job here,” Gassaway said, to cheers from the crowd who turned out a meeting held by the department as part of a process to determine whether the school should close.

“But that’s what they think about kids,” he added as part of the 11-minute address. “You don’t think that’s not done intentionally?”

With a 37 percent four-year graduation rate and a 2.4 percent college-and-career-readiness rate, Boys and Girls ranks as one of the lowest-performing schools in the city and has for years. Demand for the school has also waned, as enrollment has dropped 40 percent — from 2,000 to 1,200 — since 2010.

Department  officials have publicly pledged support for Gassaway and last spring spared the school from undergoing a grueling turnaround proposal that ultimately failed in courts earlier this year. But after another year of low performance — and an “F” grade on its latest progress report, the second in a row — the city is taking a closer look and will soon decide if it should receive the same fate as other comprehensive high schools that have shuttered under the Bloomberg administration.

The school’s status under Gassaway has been unsteady for years, but he has enjoyed the support of the Bedford-Stuyvesant community, including many influential political, business, and religious leaders. The school’s advisory board includes City Councilman Al Vann, State Sen. Velmanette Montgomery and Assemblywoman Annette Robinson, Regent Lester Young, Rev. Conrad Tillard and Bedford-Stuyvesant Restoration Corporation President Colvin Grannum.

That support was on display Tuesday night. Vann, Robinson, Young, and Tillard joined U.S. Congressman Hakeem Jeffries and about 200 others to voice their opposition to closing the school.

“There’s a lot of history here. This is part of who we are as a community and a people. You can’t close that,” said Vann.

Dozens of speakers laid out familiar arguments for why the school should be saved. Many of them said other school closures in Brooklyn and Queens had caused a large concentrations of high-need students at Boys and Girls.

“We now have to bear their burden,” said Anthony Jones, a graduate who now works with the school’s track team.

“It’s not the school that’s failing at all,” said Deanna King, a student. “It’s the people who sit there and bring 1,800 students who are terrible and bring them into our school.”

Since ex-Chancellor Joel Klein handpicked him to lead the school in 2009, Gassaway has publicly stated a desire to get rid of teachers that he considered subpar, and recently he has begun criticizing the city for not helping him do that. Still, many teachers have left under his leadership, he said, adding, ”I’m feeling more optimistic with the staff we have in place now.”

Supporters said changes Gassaway has made would take some time to have an impact. Vann said younger students will be the first to enjoy the real benefits of the reforms, which include a partnership with Long Island University, where students earn college credits.

About 25 sophomores are part of the program’s first cohort. One of them, Armando Dunn, enrolled in the program so that his mother would allow him to attend Boys and Girls and join the basketball team. Both of his older sisters had attended ultra-selective city high schools.

“I can’t send you to a school where I see statistics saying that it’s failing,” Lisa Dunn recalled telling her son.

Now, Lisa Dunn is president of the school’s parent association and said she believes Gassaway should have more time to turn the school around.

Principals of schools facing closure usually keep a low profile at the city’s “early engagement” meetings, which are run by district superintendents. But after about 90 minutes of testimony, Gassaway appeared in front of the stage and addressed the crowd.

Gassaway began by saying he was done assigning blame.

“What we can’t do, and what I may have been guilty of in the past, is we can’t point fingers,” Gassaway said. ”There are powers that be that would love to have me stand up here and bash this group or bash that group. I’m not going to do that.”

But soon Gassaway was ripping the department for its deployment of teachers from the Absent Teacher Reserve, a pool of teachers who lost their jobs through budget cuts or school closures. Gassaway said that just hours earlier he was involved in an incident with an ATR teacher who had refused to resume teaching until a disruptive student was removed from the class.

“I looked at my kids. I tell them, ‘don’t fight’, so I couldn’t fight,” Gassaway said. “But I said to myself, let me get him out of here.”

“He’s not coming back,” Gassaway added, to cheers.