For two years Dezzimond Vaughn was a well-regarded worker at the Tesla factory in Lathrop, California. Then he became involved in trying to organize a union and suddenly his job was on the line.

“They started changing rules without any remorse,” Vaughn, a 31-year-old former Tesla computer-numeric-controlled (CNC) heavy machinery operator, told the Guardian. He cited a strict attendance policy Tesla implemented and backdated that deducted points from employees every time they clocked in late or were absent. “We started talking about forming a union, because they wouldn’t be able to do the things they’re doing, and they somehow found out I was having meetings at my house.”

Vaughn claims management began to try to push him out of employment once they found out he was helping to lead unionization efforts. “Throughout my last year, we kept bumping heads. I never stopped working, they never had a problem with me as far as the work, but I had a lot of complaints about me. My supervisor said they were trying to fire me.”

In October 2017, Vaughn received a phone call at home that he was being fired by Tesla due to two poor employee performance reviews in a row. He provided his separation agreement with Tesla, which cited “failure to meet performance expectations” as the sole reason for termination. Vaughn said his review scores were changed afterward to warrant his job termination, while the positive comments from his supervisor in the review remained.

Vaughn provided a copy of his employee file and his last two employee reviews. In the reviews, his supervisor calls Vaughn an employee who “does what’s right for the company as a whole” and “can always be counted on by team members to both show up (attendance) and get the job done”, yet his review scores are low rated. In previous employee reviews (January to June 2016, June 2015 to December 2015, and January 2015 to June 2015) before management discovered his role in unionization efforts, Vaughn received high scores, which resulted in promotions.

The supervisor who conducted Vaughn’s last two performance reviews (July to December 2016 and January to June 2017), Tarus Starks, confirmed the review scores were lowered by upper management. “When Dezz came to work under me, his performance was super positive,” Starks said. “I was about to train him for back-up lead.”

“At Tesla, we strive to be a fair and just company, the only kind worth being. Performance reviews result in promotions and occasionally in employee departures,” said a Tesla spokesperson in an email. “No one at Tesla has ever or will ever have any action taken against them based on their feelings on unionization.”

The spokesperson said: “It’s worth remembering that each year, roughly 20,000 ULPs [unfair labor practice complaints] are filed with the NLRB [National Labor Relations Board] by unions like the UAW [United Auto Workers union] as an organizing tactic.”

Tesla and its billionaire owner, Elon Musk, have earned a reputation for union-busting efforts over the past few years. In February 2017, Musk accused a factory worker who outlined several issues within Tesla in a Medium blogpost of being a “union plant”. In an email, Musk also promised workers free frozen yogurt in a letter to employees that framed unionization efforts as an effort against Tesla by big car companies. The same month, Tesla employee Michael Sanchez alleged he was asked to leave the Tesla factory by security for handing out pro-union flyers outside to fellow employees.

The NLRB filed a complaint currently on trial over Musk’s alleged promise to workers in a June 2017 meeting to fix safety standard concerns if they refrained from efforts to form a union. Several similar charges against Tesla are currently under consideration by the NLRB, including one alleging surveillance and intimidation against workers attempting to form a union.

Complaints from workers over being fired for engaging in efforts to unionize at Tesla have become common. “I was a union supporter. I wore a union shirt almost every day to work and my supervisor at the time asked me why I wore it,” said Jim Owen, who left the Tesla factory in Fremont, California, in March 2018 due to concerns for his safety after a robot almost severely injured him while working on car hoods. “He told me upper management wouldn’t appreciate me wearing it.”

Mark Vasquez, worked at Tesla from 2014 until he was placed on a medical leave of absence in July 2016 after spending several months on light duty after he permanently injured his back on the job. “Talking to other workers about unionizing was really frowned upon,” he told me. “When some of my supervisors heard me talking to other employees about it, they would come over and shut down the conversation.”

One current Tesla employee, who asked to remain anonymous, was placed on medical leave after sustaining a work injury in July 2016. “They are refusing to allow me to return to work,” the worker said. “For a brief period of time, when the movement was gaining traction, pro-union employees were given promotions to lessen their demands. It did not work, so they moved to removing pro-union employees. I am one of them that they do not want back, but I absolutely will be fighting for a union even harder if I am allowed to return to work.”

A Tesla spokesperson noted the company could not share personal medical information or any details of medical leave on employees who still have pending cases with workers’ compensation.

In August 2017 Crystal Guardado was fired from Tesla as she began participating in union organizing and speaking up about the unsafe working conditions. “Some of my most vivid memories are asking questions about the union to colleagues and being told to shut up or I’d get fired,” Guardado said. She started working at Tesla in April 2017 and began speaking up after she hurt her eyes from chemicals used on door handles and was told by a doctor it was due to allergies. “They retaliated against me, I believe, because I was speaking up about my safety and the conditions in the factory.”

A Tesla spokesperson said Guardado was fired for failing the company’s substance abuse and testing policy, but Guardado argued she has possessed a medical marijuana card in California for the past five years due to panic anxiety issues and her efforts to provide human resources with the documentation leading up to the test were ignored.

Interviews with current Tesla employees suggest these alleged union busting and intimidation tactics are still being implemented by middle and upper management at Tesla factories.

“Elon Musk says he’s neutral toward the union,” another employee added. However, “They’ve been anything but neutral. Anything union or pro-union is shut down really fast.”

Another current employee in a Tesla factory who asked to remain anonymous expressed similar sentiments. “Pro-union people are generally fired for made-up reasons. There’s a culture of fear because if you don’t comply, you will be fired,” the employee told me. “We are told Tesla would go bankrupt if we unionize because we are not a profitable company yet.” He added that management quickly finds reasons to fire employees who tout their efforts to form a union and those who are fired are pushed to sign non-disclosure agreements before receiving their last paycheck.

Despite the complaints expressed by current Tesla workers, they remain committed to pushing the company to allow workers to unionize and improve working conditions.

“Why should I go somewhere else when we can make this place a good place to work and the product is an awesome product?” added one of the current Tesla employees I spoke with. “I’m proud of that fact – it’s changing the world – but it shouldn’t start on the broken backs of workers.”