The city’s correction officers who have been decrying what they call a dangerous uptick in jail violence filed a new lawsuit against Mayor Bill de Blasio and the Department of Corrections, saying they are to blame for the uptick — and the alleged coverup.

Mayor de Blasio and DOC Commissioner Joe Ponte have embraced policies that are driving violence at Rikers up — not down — including limits on solitary confinement, according to the lawsuit filed by the city’s corrections officers union.

The jump in brutality has been kept under wraps, however, thanks to massive under-reporting of violence against guards, the Manhattan federal lawsuit said.

Recent reports of declining violence at Rikers are the result of DOC’s flawed reporting policies, which are intended “to preserve the illusion” that recent reforms to reduce violence are working, the lawsuit said.

“The defendants – who are now under the watchful eye of the Department of Justice and a federal monitor — have embraced … misreporting or underreporting of the violence,” the lawsuit said.

Friday’s lawsuit, by the Correction Officers’ Benevolent Association union, cited an incident that left correction officer Tiffani Dublin with “severe spinal chord injuries” after getting punched multiple times by an inmate.

Her injury “was categorized as a mere ‘log book entry’ instead of an assault on staff,” the lawsuit said.

The DOC declined to comment, citing pending litigation. The city’s Law Department said the lawsuit is under review. The Mayor’s office didn’t return a request for comment.

In 2015, de Blasio and Ponte unveiled sweeping reforms aimed at reducing violence at Rikers to settle a class-action lawsuit that had gained the attention of the Department of Justice.

Reforms included more video cameras and reducing solitary confinement.

Last year, the DOC said the new policies had helped reduce violence at Rikers by double-digit numbers, including an 11-percent drop in violence against guards.