Education advocates in recent days have assailed job protections for New York teachers as antiquated, unwarranted and unconstitutional.

On Tuesday, the United Federation of Teachers, which represents 75,000 educators across the city, fired back. In an eight-page memo, the union argued that tenure laws help guard against unjust firings, while providing city officials with a way to remove teachers it deemed ineffective.

In the wake of a landmark California decision that struck down teacher tenure laws in June, the union is girding for an intense battle over the job protections that have long been its lifeblood.

Already, two parent groups in New York have filed lawsuits modeled on the California case, arguing that tenure laws run counter to the state’s guarantee of a quality education for all students. The groups contend that it can be exceedingly difficult to remove subpar teachers from the classroom and that veteran teachers are too often shielded from dismissal. (The California decision is expected to go through appeals.)