The UFT Charter School in Brooklyn is in danger of being closed by SUNY's Board of Trustees due to poor performance.
The East New York school first opened in 2005 as the nation's first union-run school.
But test scores show fewer than a third of the students are reading on grade level and the math proficiency rate among eighth-graders is less than half the city average.
That makes it one of the lowest-performing schools in the city.
It is one of 16 schools seeking charter renewal this year.
According to the website gothamschools.org, the renewal process began Tuesday with a visit from SUNY's Charter Schools Institute.