(NEW YORK) -- The United Auto Workers Union has filed federal labor charges against former President Donald Trump and Elon Musk, the union said Tuesday.
In a thread on X, the union said Trump and Musk had illegally attempted to "threaten and intimidate workers who stand up for themselves by engaging in protected concerted activity, such as strikes."
Musk -- who has endorsed Trump for president -- interviewed him for two hours Monday night on X Spaces in a conversation that reached over 1 million users.
During the interview, Trump praised Musk as the "greatest cutter," seemingly referring to the mass layoffs he conducted when he took over X, then known as Twitter.
"I mean, I look at what you do. You walk in, you say, 'You want to quit?" Trump said. "I won't mention the name of the company, but they go on strike, and you go, 'You're all gone.'"
Going on strike is considered protected activity under the National Labor Relations Act, and workers cannot legally be fired for doing so.
"When we say Donald Trump is a scab, this is what we mean," UAW President Shawn Fain said in a statement. "When we say Trump stands against everything our union stands for, this is what we mean."
"Donald Trump will always side against workers standing up for themselves, and he will always side with billionaires like Elon Musk, who is contributing $45 million a month to a Super PAC to get him elected," Fain continued. "Both Trump and Musk want working-class people to sit down and shut up, and they laugh about it openly. It's disgusting, illegal, and totally predictable from these two clowns."
Musk has denied reports he is contributing $45 million a month to get Trump elected. He has long been outspoken against workers forming unions, however.
On Tuesday, Musk replied to a post on X about the labor charges, criticizing Fain, responding, "The last two UAW presidents went to prison for bribery & corruption and, based on recent news, it looks like this guy will join them!"
ABC News has contacted the Trump campaign and X for comment.
Musk told BBC's James Clayton in April 2023 during a Spaces interview that the cuts at Twitter were "one of the hardest things he's had to do."