The long shot candidate is challenging Sen. Deb Fischer (R-NE) in a Trump-dominated state for a seat that has become more competitive but still favors the second-term GOP incumbent. There is no Democratic candidate.

The United Association of Steamfitters and Plumbers Local 464 is hosting a Saturday rally for Osborn that includes United Auto Workers President Shawn Fain, but the event has been tainted in controversy after members were told five days in advance that attendance at the union hall was “mandatory” and that absent members would face repercussions.

A steamfitters union instructor informed the chapter’s several hundred apprentices by email Monday that they were “required” to be at the union hall Saturday at the same time as the Osborn rally, according to emails obtained by the Washington Examiner. The message made no mention of the political event.

“You all are needed! This Saturday, October 12, you are all required to be at the hall at 11 am,” the email said. “If you are not present it will be counted as an unexcused absence. You will be required to do 2 Saturday Make ups if absent. This Saturday is MANDATORY ATTENDACE.”

A longtime union member, who was granted anonymity out of fear of retribution from union leaders against him and other members, accused steamfitters union leaders of orchestrating a political event akin to a “phantom gun” to avoid scrutiny and that apprentices feared speaking out.

“If it looks like a duck, it’s a duck,” the union member told the Washington Examiner. “If you look at the time that they’re to meet, and then they say, ‘Oh, it’s just a coincidence they’re having this rally and we’re invited, so let’s go.’”

Osborn was a former steamfitter apprentice at the same union chapter before launching his Senate bid.

“They really support Osborn. I’m okay with it,” the union member continued. “But there’s moral ethics, and when you force people to do something, where’s the free-will choice?”

Fischer and other Republicans have dubbed Osborn a “Democrat in sheep’s clothing,” an unrelenting moniker that he’s tried to distance himself from publicly by disassociating with Democrats and far-left figures, such as Sen. Bernie Sanders (I-VT). Privately, he’s continued to praise Sanders. Fain’s support has played into the GOP narrative, as he also endorsed Vice President Kamala Harris and vehemently opposed former President Donald Trump.

It was unclear whether the original mandatory rally could have run afoul of labor laws or the union’s own bylaws, but legal experts described it as an eyebrow-raising scenario due to warnings of consequences.

After the Washington Examiner reached out to the union, the same individual who sent the mandatory notice sent a follow-up email informing apprentices that their attendance would no longer be required but was still encouraged.

“Due to a conflict with other events that were recently scheduled at the hall, the mandatory JATC Saturday event will be cancelled,” the email said. “You are still encouraged to bring your families to the events that are taking place at the hall this weekend.”

Brett DaHart, the union business manager, said the initial requirement was the result of a rogue apprentice instructor and a “complete miscommunication” over other unrelated events set to occur at the union hall around the same time as the Osborn rally.

“I communicated with him and asked him to reach out to get as many people as we could to attend this event,” DaHart said in a phone interview. “He, in turn, not even having the authority or knowing what he was doing, sent out an email that it was mandatory to come. That is absolutely not the case. He had two things misconstrued on what was going on, and I will take responsibility for it because I must not have explained myself well enough.”

DaHart reiterated that members would not face repercussions and that such a threat should not have been conveyed. He said a health fair for retirees will be held indoors while the Osborn rally will take place outside in the parking lot as an entirely separate and voluntary event.

“I did ask him to ask some of the kids to come and represent because Dan is one of our members, but it was never going to be a mandatory thing to come to that event,” DaHart said of the rally.

The Osborn campaign said it was unaware of the saga and that steamfitter union leaders also informed them it was a mistake.

Fischer Campaign Manager Derek Oden said in a statement to the Washington Examiner that there was “no excuse to force [Osborn’s] own former union members to work for his campaign against their will. We encourage him to follow the law and respect those steamfitters who choose not to support him.”

Labor union legal experts suggested the union originally operated in a grey territory of the law.

“I’ve never seen a union try to level penalties against a member for not going to a political rally,” said attorney David Pryzbylski, who represents employers in union matters for Barnes & Thornburg. “I don’t know that that would be a violation of the National Labor Relations Act, but certainly, I think that could be viewed the wrong way by some people.”

Georgia State University College of Law professor Daniel Bowling said it would be one thing to invite a candidate to a union meeting to discuss political matters but that mandating a rally “would be very problematic legally, and certainly if they threatened people with punishment for not attending.”