Who should ultimately control police discipline in New York: elected officials through their appointed police commissioners, or unelected labor arbitrators chosen in part by labor unions?

The question has plainly picked up added resonance in recent days. Gov. Cuomo will soon have a chance to answer it.

Sometime before year’s end, the state Legislature must send Cuomo a bill it passed just weeks before Eric Garner’s fatal July 17 confrontation in Staten Island. The measure would allow unions representing police and other civil-service employees across the state to insist on collective bargaining of disciplinary procedures affecting their members.

The bill represents the latest in a series of attempts by police unions to nullify a unanimous 2006 state Court of Appeals decision, which affirmed the New York City police commissioner’s disciplinary authority.

The Patrolmen’s Benevolent Association had sued then-Commissioner Ray Kelly for overriding disciplinary provisions in the police contract — including a rule requiring NYPD superiors to wait at least 48 hours before questioning police officers accused of misconduct.

Oddly, Mayor de Blasio’s Albany lobbying office didn’t bother to file a memo taking a position on the bill before it passed.

But the New York State Conference of Mayors went on the record in opposition — and for good reason.

Police unions argue that disciplinary procedures should be a mandatory subject for negotiation under the 1967 Taylor Law, which governs public-sector collective bargaining. But the state Court of Appeals said Taylor could be superseded by older laws that make police discipline a matter of local control.

While “the need for authority over police officers will sometimes yield to the claims of collective bargaining . . . the public interest in preserving official authority over the police remains powerful,” Judge Robert Smith wrote for the state’s highest court.

The police-discipline bill was a classic under-the-radar, end-of-session special — an election-year favor to unions, brokered on the leadership level in both houses. It passed 57-2 in the Senate and 132-2 in the Assembly just before they adjourned in June. (Among those supporting the bill were all 42 of the Black, Puerto Rican, Hispanic and Asian Caucus members present for the votes.)

In the city, the bill would restore PBA contract provisions including the 48-hour rule. In Nassau, Rockland and Westchester, and in many municipalities elsewhere, it would overturn charter provisions and local laws designed to ensure that police discipline remains a managerial prerogative. It would also block towns and villages from passing their own laws superseding collectively-bargained police disciplinary provisions.

Localities with such laws typically mandate an internal hearing process that gives the final say on punishment and penalties to an elected board or council. In New York City, the police commissioner has the final say.

Unions, by contrast, prefer to have disciplinary charges referred to autonomous “impartial” labor arbitrators — similar to the system that makes teacher discipline a costly and time-consuming hit-or-miss proposition.

This year’s bill is only the latest in at least four attempts by police unions — and their friends in both parties and both houses of the Legislature — to roll back the Court of Appeals’ police-discipline ruling of March 2006. The last three governors all vetoed similar bills.

Many New Yorkers sympathetic to police may be inclined to side with the PBA’s agenda. But responsibility for police discipline transcends issues such as de Blasio’s policy changes on stop-question-and-frisk, or the strong feelings aroused by the Garner case.

It’s not just that resisting the union’s push is consistent with democratic accountability. Preserving this fundamental managerial prerogative for the police commissioner is in the best interest of the police department. As police historian Thomas Reppetto says, “The NYPD has always run best when the police commissioner clearly was in charge.”

Cuomo will now have his own chance to weigh in. On top of vetoing this clear usurpation of local control, he should send the Legislature a stronger message: From this point on, he won’t sign any bill covering an important statewide public policy issue that is whisked to passage with virtually no notice, deliberation or public hearing.

E.J. McMahon is president of the Empire Center and a Manhattan Institute senior fellow.