Tesla fired more than 30 workers at its Buffalo Gigafactory Wednesday, just a day after workers announced their intentions to unionize.

Workers United, the union partnering with Tesla workers, filed a complaint with the National Labor Relations Board (NLRB) alleging Tesla terminated 18 employees "in retaliation for union activity and to discourage union activity."

A statement from the union said that more than 30 employees were fired. It said the firings came on the heels of the union organizing effort announced earlier this week.

"These firings are unacceptable," the statement said in part. "The expectations required of us are unfair, unattainable, ambiguous and ever changing. For our CEO, Elon Musk, to fire 30 workers and announce his $2 billion charity donation on the same day is despicable. We stand as one."

The Workers United complaint asks the NLRB for an injunction to "prevent irreparable destruction of employee rights resulting from Tesla's unlawful conduct." Workers United has helped unionize hundreds of Starbucks cafes across the country.

"I feel blindsided," said Arian Berek, one of the fired employees quoted in the union's statement. "I got Covid and was out of the office, then I had to take a bereavement leave. I returned to work, was told I was exceeding expectations and then Wednesday came along. I strongly feel this is in retaliation to the committee announcement and it's shameful."

Tesla Workers united Twitter account shares the groups thoughts on the news of recent firings at the company's Buffalo Gigafactory.

Workers also received a company email Wednesday evening informing them of a new policy banning them from "recording workplace meetings without all participants' permission," according to the statement.

The statement explained that the company policy violated federal labor law as well as New York's one-party consent law to record conversations.

Tesla CEO Elon Musk has taken a hard line against unionization attempts in the past, previously being ordered by the NLRB to delete a 2018 tweet in which he unlawfully threatened workers with loss of stock options if they chose to be represented by the United Auto Workers union.