Mayor’s Peters principle

Never has a mayor of New York dared fire the anti-corruption watchdog who guards City Hall. With seven pages drafted by his lawyers earlier this year to deliver the justifications the law says he must, Mayor de Blasio this spring came to the brink of firing Mark Peters as commissioner of the Department of Investigation — and still has the papers on file.

As if he could ever have gotten away with canning the top cop on the beat exposing his administration’s grievous breakdowns and mandating reforms.

Lead paint poisoning children at NYCHA. Swiss cheese child abuse investigations that left other kids dead. Smuggling into city jails, and top Correction brass’ rampant use of city vehicles for personal trips. The sheer incompetence behind the Rivington House nursing home debacle.

Compare that record to the reasons the drafters of the mayor’s memo give to justify firing Peters.

Peters moved to fold into his office the formerly independent Special Commissioner of Investigation for the Department of Education; no one disputes that. De Blasio alleges, and he’s technically likely right, that Peters had no authority to make that move — and badly botched his job offer to the woman in charge, then fired her after she complained about a reorganization.

And that, separately, Peters threw a snit about office space for his staff, supposedly invoking that he had “people with guns in the room” with the power to make arrests. And used similarly heated language when throwing his weight around with then-budget director Dean Fuleihan.

That’s it? That’s it.

That de Blasio keeps the means close at hand to eject his onetime friend and campaign treasurer lays bare two ugly possibilities about his motives.

The mayor is either ready to rid himself of the source of probes that are forcing correction of calamitous mistakes by his administration — or wildly overreactive to Peters’ admittedly brash, at times obnoxious leadership style.

Two years into de Blasio’s first term, the Daily News called for Peters’ resignation on the view — well justified by early investigations that failed to name names or specify sufficient remedial actions — that his close personal relationship with de Blasio precluded the intensive probes this mayor merited.

Peters has since well proven his independence and zeal. The mayor in his target sights has evidently noticed.