The United Federation of Teachers is trying to get involved in the lawsuit challenging teacher tenure laws.
The UFT filed papers seeking to become a defendant in the case filed by the New York City Parents Union on Staten Island earlier this month.
Currently, the lawsuit names education officials as the defendants.
The teacher's union says it can offer the court a perspective on why tenure—or lifetime job protections—is an important component of teachers' contracts.
The lawsuit comes after a group of California parents toppled teacher tenure laws there in June.
In New York, teachers are eligible for tenure after three years in the classroom.