Heralded as one of the faces of the Democrats’ emerging progressive wing just a year ago, New York City mayor Bill de Blasio could lose out on hosting the party’s 2016 convention due to recent tension between his administration and city police, according to a new report. In recent weeks, the New York Police Department has taken issue with de Blasio’s comments towards the city’s policing and blames the mayor for fueling anti-cop sentiments.

“[DNC officials are] worried about the optics,” a source familiar with the DNC told the New York Daily News, referring to recent episodes of NYPD officers turning their backs to de Blasio, as well as citywide protests against the NYPD led by local activists. “They don’t want side stories. The story should be the convention.”

Moments like what took place on Wednesday, in which an NYPD supporter flew a plane over the city with a banner reading, “De Blasio, Apologize to the NYPD!!” only add to the DNC’s hesitation to host the convention in the Big Apple. New York — more specifically, Brooklyn’s Barclays Center — is one of the three finalists to host the event in summer of 2016, along with Philadelphia and Columbus, Ohio.

Cops aren’t making it any easier for de Blasio or DNC officials: In August, the Sergeants Benevolent Association, a police union in the city, paid for two full-page ads opposing New York as the site for the convention, and encouraging Democrats to look elsewhere.

After a strained year with the NYPD, de Blasio angered police once more in the final hours of 2014 by reappointing a Brooklyn judge who freed two gang members who threatened police last month, just days before the execution-style deaths of officers Rafael Ramos and Wenjian Liu, to another term

“[De Blasio] had the opportunity to demonstrate good will and support for the police, and he once again has demonstrated the opposite,” a police union leader said after news of the reappointment, according to the New York Post.

Those sorts of instances are doing little to help de Blasio’s case. “I think people are going to say it was a rejection not just of the city, but of the de Blasio administration,” the DNC source told the Daily News.