On Monday night, the labor union working with employees at Kickstarter filed a charge with the National Labor Relations Board accusing the crowdfunding company of wrongfully terminating two workers, Clarissa Redwine and Taylor Moore. As Slate first reported, Moore was fired last Thursday, just eight days after Redwine’s dismissal. Both had been key organizers of the unionization effort, which went public this March. Kickstarter told Slate last week that it has never fired anyone for union activity.

Workers at the company told me last week that they believed Moore and Redwine were fired because of their union organizing. A third employee at Kickstarter, who was also a core organizer since the beginning of the union drive, was told by senior managers to find employment elsewhere last Thursday, according to five sources within the company.

The charges, filed by the Office and Professional Employees International Union Local 153, allege that Kickstarter singled out Moore and Redwine because of their union activity and that the firings were retaliatory. The charges further allege that Kickstarter interfered with employees’ right to organize, since such firings could have a chilling effect on union efforts. Moore and Redwine are asking for back pay and to be reinstated to their positions. Next, the NLRB will ask the union to file an affidavit describing the charges, and the employer will have to respond.

Slate asked Kickstarter to comment on the NLRB charge Tuesday morning, and this post will be updated when the company responds.

In May, Kickstarter CEO Aziz Hasan told staff that the company would not voluntarily recognize the union if asked, but would respect employees’ decision if they voted to form one through a secret ballot. Five sources have told Slate that the majority of nonmanagers at the company have pledged to join the union. If the drive is successful, Kickstarter will be the first well-known tech company with a white-collar union.

Kickstarter has been known as one of the more progressive workplaces in tech for several years. It became a “public benefit corporation” in 2015, meaning the company vowed to never take Kickstarter public and to measure the company’s success by how well it adheres to its values rather than how much money it makes. But multiple current and former employees I interviewed feel that their employer hasn’t been reflecting its outward values internally—a tension that became heightened during a controversy last summer over a Kickstarter drive for a satirical “Nazi-punching” comic book that senior leaders wanted to take down. The sources say that in companywide meetings this spring and early summer, Kickstarter leaders explained why it thought Kickstarter should not have a union, saying that it would be costly, make the company less agile, and would distract employees from other work at the company.

Redwine, who had worked on the outreach team at Kickstarter since 2016, regularly signed emails from the union’s organizing committee that were shared with staff. When she was fired earlier this month, Kickstarter leadership told her colleagues that Redwine’s termination was a result of long-standing issues related to her performance. Typically at Kickstarter, when employees have issues related to their work, the company puts them through a “performance improvement plan,” a process in which managers help workers get back on track, according to five current and former employees at the company. But Redwine wasn’t put on one, despite being told that she would, and instead was fired, according to five former and current employees at Kickstarter. Several workers told me that Redwine had been under increased scrutiny from senior managers for months. Last Monday, Redwine and the Office and Professional Employees International Union filed an unfair labor charge with the National Labor Relations Board, alleging that the severance agreement offered to her by Kickstarter contained an illegally phrased nondisparagement clause. Kickstarter told Slate that it had sent an email to Redwine with an offer to narrow the clause, but she never replied. Redwine told Slate that she feels “strongly that any agreement that treats severance as repayment for silence is an unethical one.”

Moore, an employee at Kickstarter for six years, was also a core union organizer who regularly signed emails from Kickstarter United, the name of the effort. He worked on the same team as Redwine. Unlike Redwine, Moore had completed a performance improvement plan, which he was put on after the union drive went public. The union effort said in a statement last week that the firings were “unexpected” and “retaliatory.”

The Kickstarter employee and union organizer who was told to find employment elsewhere did not respond to requests for comment. Slate also asked the company about this worker and will update this post with its response.

Since the news broke last Thursday about the firing of two union organizers, some project creators and backers on Kickstarter have launched petitions in support of the union drive. A petition started by Current Affairs—a magazine that fundraised to publish its first issue on Kickstarter in 2015—now has more than 100 signatories of project creators who, as of Sunday, represent around $3 million in total fundraising collected on the site, according to one of the petition’s organizers, Nathan Robinson. Artist and author Molly Crabapple tweeted on Sunday that she, too, had signed the petition. “I owe my fine art career to Kickstarter,” Crabapple tweeted. “It is a site I love, and a site that changed my life. They need to recognize the union.” While many creators shared that they would halt their fundraising if management fails to recognize the union, organizers of the union drive clarified that “we are not calling on creators who rely on Kickstarter to abandon live or planned projects.”

Update, Sept. 17, 2019, 9:36 p.m.: Kickstarter responded to Slate’s questions about the NLRB charge as well as the third union organizer who sources say was told to find new employment last week: “We’d like to reiterate that these employees were not singled out because of their organizing activities,” a company spokesman wrote. “We’ve terminated three other people who were not union organizers since March, when the organizers announced their effort. We’ve also given raises to 14 people who were public about their support for the union, and promoted three of those people. We can’t suspend the routine operations of the company while the staff considers whether a union is right for them.”

Read the full report on the unionization effort and tensions at Kickstarter here.