Mayor Bill de Blasio's administration will not support an effort by the City Council to remove the police commissioner's final authority over disciplinary matters, breaking with progressive lawmakers and reform advocates who are working to roll back the longstanding power.

The revelation came during a City Council hearing on Tuesday concerning a portion of the sweeping police reform package introduced by the body late last month. Bills to end qualified immunity for officers in certain cases and to give the council a role in selecting the police commissioner will also be opposed by the administration, according to the mayor's representative at the hearing, Chelsea Davis.

The mayor's swift rejection of the proposals comes as New York City faces a state-imposed deadline to adopt a set of reform practices by the end of March. Adrienne Adams, the chair of the Public Safety Committee, said the council was forced to introduce their own measures because of the mayor's ongoing refusal to release a draft of his reform plan.

In response, representatives for the mayor and the NYPD touted a newly adopted disciplinary matrix, and a memo of understanding stating that the police department would more closely follow the recommendations issued by the Civilian Complaint Review Board going forward. That matrix is not legally-binding nor particularly detailed, and does little to address the NYPD's years-long pattern of ignoring discipline recommendations issued by the CCRB, according to police accountability advocates.

"Past is prologue," said Councilmember Stephen Levin, pointing to an analysis that found that penalties issued by NYPD leadership diverged from the watchdog's recommendations in 71% of cases. "If the administration believes everything it's saying about the disciplinary matrix then why wouldn't they get behind a push to remove the police commissioner’s final disciplinary authority? Frankly it's not really a defensible position."

In her testimony, Davis acknowledged that the lack of concurrence between the CCRB and the police commissioner was a "major issue we're looking to address." But she maintained that stripping the commissioner's authority, which would require legislation at the state level, could set up a series of "unintended consequences" related to the NYPD's collective bargaining agreement.

When Levin described that response as a "red herring," Davis went on to suggest that other cities that don't grant their commissioners authority over discipline still face issues of police misconduct.

NYPD attorney Oleg Chernyavsky, meanwhile, offered a more blunt defense of the existing order: "Ultimately it's the agency head having control over the personnel in his organization."

The bill's sponsors say they're hoping to move forward with a vote ahead of the state's April 1st deadline.