Teamsters President Sean O'Brien on Tuesday slammed Donald Trump for his comments to Elon Musk suggesting workers who go on strike ought to be summarily fired.
"Firing workers for organizing, striking, and exercising their rights as Americans is economic terrorism," he told Politico.
Trump on Monday complimented Musk's ability to cut costs by saying he would not tolerate workers going on strike.
"You're the greatest cutter," Trump said during a 2-hour conversation with the Tesla CEO.
"I mean, I look at what you do. You walk in, you just say: 'You want to quit?' They go on strike — I won't mention the name of the company — but they go on strike. And you say: 'That's OK; you're all gone.' So every one of you is gone."
The Auto Workers Union on Tuesday filed labor charges with the National Labor Relations Board against both Musk and Trump "for their illegal attempts to threaten and intimidate workers who stand up for themselves by engaging in protected concerted activity, such as strikes."
Under federal law, workers cannot be fired for going on strike, and threatening to do so is illegal under the National Labor Relations Act, the UAW said in a statement. It is unclear whether the NLRB would take action against Trump for his comments, but the UAW jumped on his remarks as it continues to rally behind Democratic presidential candidate and Vice President Kamala Harris and encourage its nearly 400,000 workers to vote for her over Trump, especially in battleground states like Michigan that could determine who wins the White House in November.
The UAW endorsed Harris at the end of July.
O'Brien last month became the first union leader to speak at the Republican National Convention.
The International Brotherhood of Teamsters is the largest union not to endorse Vice President Kamala Harris. The Teamsters National Black Caucus on Tuesday broke with its parent organization and voted unanimously to endorse Harris.
Information from Reuters was used in this report.