NYPD Commissioner William J. Bratton will release statistics Monday that confirm the police work slowdown involving summonses and minor crimes has ended.

Last Friday, Bratton told reporters that he wasn't entirely certain why his officers were writing drastically fewer summonses and making fewer arrests in the past two weeks.

"All I'm concerned with is the officers going back to work," said Bratton, who is expected to give reporters a briefing Monday on the statistics.

In a statement, de Blasio said he was gratified the slowdown had ended and wanted cops to continue working closely with communities.

But even if police go back to their former routines, there appears to be some deep seated problems with rank-and-file officers that may impact police activity. Law enforcement and union officials who have been talking to NYPD officers find that the recent killings of officers Wenjian Liu and Rafael Ramos last month in their patrol car and the anti-cop rhetoric after a grand jury failed to indict Officer Daniel Pantaleo in the chokehold death of Eric Garner have rattled them and further hurt morale.

"They are feeling threatened," said one high-ranking city law enforcement official who declined to be named.

For the cops, the threats seem to be coming not only from the criminals on the street but also a political environment in which they fear an honest mistake may lead to an indictment.

They cite the fatal shooting of Akai Gurley by rookie Officer Peter Liang in a dark public housing stairwell in Brooklyn in what police said was an accidental discharge. Gurley's family has asked the case be investigated as a homicide. De Blasio and Bratton have called the shooting a tragic accident. The case will be going before grand jury, Brooklyn prosecutors have said.

"They are not engaging people because of that fear,' said the official about the cops' reluctance.

The killings of Liu and Ramos underscored the constant dangers for police. But their deaths were doubly shocking for many new officers, an estimated 16 percent to 25 percent of whom weren't on the force when officer Russel Timoshenko died in 2007, gunned down during a Brooklyn traffic stop.

Officers, who have turned their backs on de Blasio at funerals for the fallen officers, believe it is just a matter of time before a cop in an accidental situation is treated as a murderer, the official added.

The issue was raised last week during a meeting Bratton had with top police union leaders, said Edward Mullins, president of the Sergeants Benevolent Association. When the decline in quality of life summonses was discussed one union official bluntly noted that Garner's death and the resulting turmoil started with the sale of loose cigarettes, said Mullins.

"Who wants to be that guy?," said Mullins of the cop seen on video taking down Garner, who was overweight and asthmatic, with a chokehold.

"There is a lot of uncertainty," agreed police author and historian Thomas Reppetto on the impact of the Garner case on cops.

The anti-police sentiment expressed in the Garner demonstrations in which some protesters labeled officers as racists, and initial comments by City Hall about "alleged" assaults on officers clearly shown on video, further demoralized officers, said Mullins.

"In the end people cannot go to work every day in an atmosphere where they feel they will be in trouble or indicted," Mullins stressed.

Asked about the slowdown, Brooklyn Borough President Eric Adams, a former NYPD captain, said at a Brooklyn news conference: "I think many of them were traumatized by the awful assassination. I think that some of the officers may have had a misdirected feeling of anger.

"But we are professionals . . . there may have been a slowdown on some of the minor traffic and summons-writing, but there was definitely not a slowdown on police protection," Adams said.

With Emily Ngo