Mayor Bill de Blasio may be well ahead in the polls, but unions representing tens of thousands of city workers are still sitting on the sidelines. NY1 Political Reporter Courtney Gross has learned that the unions' decision to stay out of the race may carry through Election Day. Here's her exclusive report.

One of Bill de Blasio's first tasks as mayor when he entered office in 2014 was to make sure every city union had a contract.

He negotiated a lot. But that is not translating on the campaign trail as he seeks a second term.

"At this point in time, my union is going to be on the sidelines. We will not be taking an endorsement in this year's mayoral race," said Roy Richter of the Captains Endowment Association.

"We haven't endorsed in the mayor's election," Correction Officers' Benevolent Association President Elias Husamudeen said on "Road to City Hall" on Oct. 4.

In fact, NY1 has learned that a coalition of at least 16 unions of uniformed workers, led by the police detectives, will not be weighing in on the race, having failed to reach an agreement on a candidate. That coalition includes tens of thousands of city workers, including those in the fire, sanitation, and corrections departments.

Right now, one source explained the decision as "staying neutral."

In 2013, the same coalition backed Democrat Bill Thompson.

Separately, major unions like the Patrolmen's Benevolent Association and the Sergeants' Benevolent Association have stayed on the sidelines.

A source told NY1 that the police officers' union is undecided. The head of that union, Pat Lynch, would not discuss it with NY1 on camera. The union's contract expired in August. Already, the union says negotiations on a new one are at an impasse.

Perhaps it's indicative of the fraught relationship the mayor has had with police unions — no one expected them to be in his corner now.

Some of them certainly see the benefits of staying quiet. "We felt that the best course of action, and the one that is in the best interests of our members, is to maintain the lines of communication and not take an endorsement," Richter said.

Staying out of the race could help these unions during future contract negotiations. One could say that when they go to the negotiating table there won't be any bad blood left over from the election cycle.

In response to this story, a spokesman for the mayor's campaign said de Blasio strongly supports the uniformed men and women who serve New York City every day.