Chicago Mayor Lori Lightfoot (D) was humiliated over the weekend when she was drowned out by boos during a union fundraiser.

The Chicago Sun Times reported that Lightfoot was not welcomed with open arms at an annual fundraiser Sunday for Plumbers Union Local 130, the first union that endorsed her 2019 runoff election. The union has since turned on her, with one attendee saying that Lightfoot was “booed off the stage” after speaking for less than a minute.

“Almost deafening,” the person revealed. “I was sitting at the table with a bunch of plumbers. They’re like, `We’ve never heard that before here.’ … Clearly, their membership is not with her. … They were calling her names. It was bad.”

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Video that has since gone viral on social media shows Jim Coyne, the union’s business manager, introducing Lightfoot and a loud round of boos erupting as she took the podium.

“I knew that was going to happen,” one person can be heard saying off camera in the video. “That’s f—-ing brutal.”

Pat McCarthy, the union’s recording secretary, tried to downplay the reception Lightfoot got by saying that she was able to finish her speech.

“I was there when she was speaking. There were a couple of people in the corner that booed. But it was nothing significant. And it didn’t disrupt the event at all,” McCarthy said. “I would have to suspect whoever was booing at that event was not a member of this local. … We respect her and we have no problems with the mayor.”

Dave Mellet, Lightfoot’s political director, claimed that he’s confident the union will endorse the mayor’s reelection in 2023.

“I don’t believe that she was, quote-unquote, ‘booed’ at this event,” he alleged. “I believe she was well received. There may have been a couple of people in the room who came in there to shout and be loud.”

Unions have turned on Lightfoot over her vaccine mandate, which requires city workers to report their COVID-19 vaccination status or be placed on unpaid leave. Fraternal Order of Police (FOP) President John Catanzara has said that it’s not just his unit that is against her now, as it’s also first responders, firefighters and labor unions that oppose the mandate.

“We’re going to see just how many officers we’re really talking about the city can literally lose in a blink of an eye if this mandate doesn’t change sooner rather than later,” Catanzara said this week, according to ABC7.

Despite all of this, Lightfoot has continued to stand by her vaccine mandates. It remains to be seen if this will come back to bite her in her next election.