PALO ALTO — A new lawsuit alleges Tesla’s factory floor is a “hotbed for racist behavior.”

In the suit, former assembly worker Marcus Vaughn, who said he was fired from the electric car maker for “not having a positive attitude,” claims supervisors and co-workers called him the n-word, but his written report to human resources about it drew no investigation.

In a blog post responding to the lawsuit, filed Nov. 13 at California Superior Court in Alameda County, Tesla pointed to behavior and disputes among workers.

“Several months ago we had already investigated disappointing behavior involving a group of individuals who worked on or near Marcus Vaughn’s team,” Tesla said. “At the time, our investigation identified a number of conflicting accusations and counter-accusations between several African-American and Hispanic individuals, alleging use of racial language, including the ‘n-word’ and ‘w-word,’ (a slur against Latino people) towards each other and a threat of violence.

“After a thorough investigation, immediate action was taken, which included terminating the employment of three of the individuals,” Tesla said.

Vaughn’s lawsuit seeks certification as a class-action, to bring in current and former African-American Tesla factory workers.

“Although Tesla stands out as a groundbreaking company at the forefront of the electric car revolution, its standard operating procedure at the Tesla Factory is pre-Civil Rights Era race discrimination,” the lawsuit alleges. “Race harassment has continued at the Tesla Factory, and became more widespread, because despite their knowledge of the harassment, Defendants have done nothing that could be reasonably expected to stop it.”

Vaughn’s legal action is the third lawsuit filed this year by black workers alleging racial slurs were used against them and that the company ignored their complaints. It is the first such suit to seek class-action status.

Vaughn claimed in the suit that shortly after he started working at Tesla in April, supervisors and co-workers began targeting him for harassment on the basis of his race. The n-word was used against him “on a regular basis,” and he witnessed the use of the slur toward other black employees, he claimed. He said he was fired in October.

His legal complaint included a memo it said was from Tesla CEO Elon Musk to employees. In the reported May 31 memo, Musk appeared to push back against minority workers’ grievances.

“Part of not being a huge jerk is considering how someone might feel who is part of [a] historically less represented group,” Musk wrote in the emailed memo, according to the lawsuit. “Sometimes these things happen unintentionally, in which case you should apologize. In fairness, if someone is a jerk to you, but sincerely apologizes, it is important to be thick-skinned and accept that apology.”

Vaughn’s lawsuit took issue with the purported response from the Tesla chief to problems in the workplace.

“In light of CEO Musk’s message to employees that racist epithets can be directed ‘unintentionally’ and that it is ‘important to be thick-skinned,’ it is not surprising that the Tesla Factory has become a hotbed for racist behavior,” the suit said.

Tesla, in the blog post, said Musk’s letter was intended to make sure “Tesla employees always try to do the right thing, that being a jerk is not allowed, that everyone should be contributing to an atmosphere where people look forward to coming to work in the morning and that no one should feel excluded, uncomfortable, or unfairly treated.”

The blog post included the a copy of the letter, in which Musk appeared to refer to bad behavior by minority employees, who he said “have endured difficulties that someone born and raised in a more privileged situation did not.”

But, he said, “If you are part of a less-represented group, you don’t get a free pass on being a jerk yourself,” he wrote.

Vaughn incorrectly characterized himself in the suit as a fired employee, when he was a temp from an agency, and had reached the end of his six-month placement, Tesla said. Vaughn is seeking unspecified general and punitive damages under California anti-discrimination law.

Tesla said there would be “further action” at the company that would include “parting ways with anyone whose behavior prevents Tesla from being a great place to work and making sure we do everything possible to stop bad behavior from happening in the first place.”

However, with 33,000 workers, and more than 10,000 at the Fremont factory, “it is not humanly possible to stop all bad conduct, but we will do our best to make it is as close to zero as possible,” Tesla said in the blog post.

The firm said it opposed any discrimination, harassment or unfair treatment.

“Tesla is absolutely against any form of discrimination, harassment, or unfair treatment of any kind,” the blog post said. “When we hear complaints, we take them very seriously, investigate thoroughly and, if proven to be true, take immediate action.

“Everyone at Tesla, without exception, is required to go through an anti-discrimination course. Our human resources team also conducts regular in-person spot training sessions when an allegation or complaint has been made, even if the evidence is not conclusive enough to warrant disciplinary action.

“We have also created a dedicated team focused exclusively on investigating workplace concerns, recommending corrective actions and assisting managers with implementing those actions,” Tesla said.

On top of lawsuits, Tesla is facing criticism over its failure to meet production targets for its entry-level sedan, the Model 3.