One of Missouri's largest public-sector unions is demanding its former president pull an ad supporting right to work.

Retired St. Louis Police sergeant Gary Wiegert urged voters to support Proposition A, which would ban employers from mandating union membership dues or fees as a condition of employment. Wiegert, the former head of the St. Louis Police Officers Association, criticized "out of touch union officials" for "lying to you about Prop A."

"I'm a retired union leader. If workers like their union they can keep it," Wiegert says in the ad, which has garnered more than 3,000 views on the National Right to Work Committee's Facebook page. "Prop A just gives them that choice … Prop A is good for our workers."

The association, which publicly backs rejecting right to work, took issue with the ad because Wiegert appears in a union polo shirt. The union sent a cease-and-desist letter to take down the "misleading" ad, which has aired on local radio and television airwaves.

"It is patently obvious that you and the [Yes] campaign are using our copyrighted logo without permission to intentionally mislead Missourians that the SLPOA or its members sanction your anti-worker rhetoric," the letter says.

The letter emphasized that Wiegert was banned by the union in 2012 for "unauthorized activities that violated our bylaws" and no longer maintains any ties to its leadership. The union vowed to "pursue all available legal remedies" against Wiegert and right-to-work supporters associated with the ad if it does not address the use of the logo.

"Sgt. Wiegert's anti-worker positions are no secret to our organization, he has been vocal about them for years," union spokesman Jeff Roorda said in an email.

Wiegert told the Washington Free Beacon he has pulled a link to the video down from his Facebook page. He said the cease and desist letter strikes him as intimidation and an attempt to silence his beliefs as a warning to other current or former union members who may support right to work. He was critical of union leadership, saying the association was "no longer run by actual police officers, but Democratic hacks."

"They're trying to intimidate you anyway they can. That's politics, I guess. I was surprised it [the letter] was so petty," he said. "I think they're just trying to attack anyone who tries to stick their heads up…Because I spoke out and am a former union leader, they're going to come out after me."

Roorda said Wiegert's free speech rights do not include the use of union trademarks or to infer a continued relationship with the union.

"We honor and hold sacred Sgt. Wiegert's First Amendment rights. However, he doesn't have a right to misrepresent his status with our organization or to use our copyrighted logo," he said. "That is the activity we have demanded that he cease and desist. Gary is otherwise free to espouse his opinions no matter how anti-worker and anti-police those opinions may be."

One St. Louis law enforcement officer, who spoke on condition of anonymity, said the dispute between Wiegert and the association stems from politics. He said Wiegert was widely known as a "fixture in conservative Republican circles" even as a union official.

"They just want to sabotage his commercial. [Labor groups] don't want to leave anything to chance," the officer said. "They know he's not some union buster—he's just getting [criticized] because he's a conservative."

The officer emphasized that even if Prop A passes, he will continue his membership in his department's union. He was, however, uncomfortable with how SLPOA was treating one of its former leaders.

"I have a great union. It provides an outstanding package of benefits," he said. "My union earned my vote."

In 2017, the Republican-controlled state legislature and since-ousted Gov. Eric Greitens approved legislation to make Missouri, a traditional union stronghold, a right-to-work state. Labor officials mobilized across the state to put the law on the 2018 ballot in a last minute bid to block it. The issue has since become one of the most contentious campaigns in the state, attracting $20 million in contributions. The pro-union Vote No campaigns hold a three-to-one fundraising advantage with more than $15 million raised and have spent $8.7 million campaigning compared with $3.5 million from pro-right-to-work groups, according to Ballotpedia.

The dispute over the ad has drawn criticism from others involved in the debate over right to work. Akash Chougule, a spokesman for Americans for Prosperity, which has launched an extensive education campaign about right to work across the state, said the union should respect Wiegert's choice to speak out.

"It's no surprise to see opponents of right to work trying to deprive someone of their First Amendment right to free speech. The idea that an individual might be able to think for himself is preposterous to many supporters of forced unionism," Chougule said. "Being in a union simply isn't right for everyone, and they should have the freedom to make that choice and the freedom to say so."

The National Right to Work Foundation also said the association's reaction to Wiegert's position demonstrates the disconnect between workers and labor officials.

"This type of bullying is exactly why Missouri needs the protections Right to Work laws offer," Foundation President Mark Mix said in a statement. "The fact that these are the lengths union officials are willing to go silence any dissent among rank-and-file workers demonstrates exactly why every worker should be able to refrain from supporting a union if they choose."

The voter referendum will take place on Aug. 7.