Tesla CEO Elon Musk and synthpop musician Grimes are a union, the newly minted couple announced this month. What’s not a union: workers at Tesla’s factory, where employees have accused management of union-busting.

Yet on Twitter Monday night, Grimes on Twitter called reports of union-busting “fake news.”

Employees have publicly rallied for a union since early 2017, citing injuries and burnout assembling Tesla cars. Those employees previously accused management of attempting to intimidate workers out of a union drive, and leaked emails show Musk slamming the organized labor effort.

Grimes, an indie artist, has previously hyped her leftist credentials. Until recently, she called herself an “anti imperialist” in her Twitter biography. Lyrics from her most recent album bash the music industry for pushing her into “commodifying all the pain.”

Since the couple went public at the Met Gala earlier this month, some of Grimes’ fans have pressed her on Tesla’s alleged anti-union efforts.

On Monday night, Grimes replied to one such fan on Twitter.

“he has never prevented them from unionizing it's quite literally fake news,” she wrote. “trust me, i've investigated this heavily and even visited factories etc,” she wrote on Monday. “i have the receipts but since it effects others i’ll wait til i ama w imminent new music b4 i answer more queries.” Grimes deleted the tweets, and did not offer any of the promised receipts. Hours later, Musk waded into the debate, claiming that he was not preventing his employees from unionizing, but that they chose not to because they would have to “pay union dues & give up stock options for nothing.”

Pro-union employees who spoke to The Daily Beast last August alleged a subtle intimidation campaign by the car company.

“Every time we go out there and try to hand out flyers, security comes and talks to us for 20 to 30 minutes, takes our badges, makes sure we’re employees of the factory,” Alan Ochoa, a pro-union Tesla worker previously told The Daily Beast of efforts to unionize in the factory. “Sometimes people from HR come, and they don’t hold back on their opinions on the matter.”

Ochoa said he’d sustained a permanent injury from repeated motions on the factory floor. He was diagnosed with painful carpal tunnel that left him unable to change gears in his own car, let alone build cars for others.

Another employee told the Guardian he’d seen colleagues collapse on the factory floor, and that employees were told to work around the body.

The alleged anti-union efforts came from the top of the company, a leaked email by Musk to employees suggested. The email came shortly after an employee published a blog post describing workplace injuries and calling for a union. In the email, Musk bashed the union effort as a money-grabbing ploy by the United Auto Workers, and promised employees “fun” perks instead of collective bargaining.

“As we get closer to being a profitable company, we will be able to afford more and more fun things,” Musk wrote in the February 2017 memo, obtained by BuzzFeed. “For example, as I mentioned at the last company talk, we are going to hold a really amazing party once Model 3 reaches volume production later this year. There will also be little things that come along like free frozen yogurt stands scattered around the factory and my personal favorite: a Tesla electric pod car roller coaster (with an optional loop the loop route, of course!) that will allow fast and fun travel throughout our Fremont campus, dipping in and out of the factory and connecting all the parking lots. It’s going to get crazy good.”

Musk’s email also scoffed at claims that Tesla had a workplace injury problem. But reports of on-site injuries have persisted. This April, the Center for Investigative Reporting released an investigation accusing Tesla of skipping some safety measures and misclassifying some injury reports to keep their safety figures friendly. When a person tweeted the link at Musk on Tuesday, the Silicon Valley exec dismissed the report as “bs.”

He went on to slam UAW, the union with which his employees are still trying to organize. UAW “want divisiveness & enforcement of 2 class ‘lords & commoners’ system. That sucks,” wrote Musk, a billionaire. “Managing sucks btw. Hate doing it so much.”