He's been trailing in every poll conducted so far, but Scott Stringer's campaign for mayor continues to rack up support.

On Monday evening, the United Federation of Teachers threw its support behind the city comptroller.

UFT President Michael Mulgrew cited a years-long relationship and Stringer's experience in city government.

"As a school system and as a city, we will be facing unprecedented challenges, and we are going to need someone who knows how to get the job done," Mulgrew said.

The union endorsement is a much needed boost for Stringer, whose campaign has struggled to get off the ground despite wide establishment support and the backing of several progressive groups, including the Working Families Party.

"Teachers vote. Teachers work. Teachers know what's at stake," Stringer said, flanked by a small group of union members who gathered at UFT headquarters to announce their pick.

With this latest endorsement, the city's political establishment and some labor unions are now solidly behind Stringer. He's the longest-serving politician in the wide field of candidates, and he says he's now got the momentum needed to win a race he believes most New Yorkers are just tuning into.

"We're going to make sure that every child, in every zip code, in every neighborhood has a chance to make it in this city," Stringer said. "This race is getting started, I've known to close strong, and this union closes strong."

That theory will be put to the test.

In some ways, the endorsement is a trial of political relevance and power for the UFT. The union, which represents more than 200,000 public school educators, has failed to pick a winning candidate in recent elections.

"The mayor's race, the last couple of rounds has not gone the way we wanted. But we will continue to do our work the proper way, which is to try and figure out which is in the best interest of our school system and our city," Mulgrew said.

Stringer is familiar with the system. Both of his two young kids are in city schools. He often speaks about major issues currently facing the union, most importantly the full return to in-person learning after the pandemic shut schools down last year, the integration of remote teaching, and a troubling rise in student homelessness.

The endorsement means the Stringer campaign will get an army of volunteers to campaign on his behalf ahead of the June primary.

Asked if the union would eventually get behind another candidate if Stringer does not secure the nomination, Mulgrew would not entertain the question, saying he is confident his chosen candidate will deliver a win.