Hundreds of OpenAI staffers are calling for the resignation of the ChatGPT company’s board, and threatening to quit themselves, after a tumultuous weekend that began with the surprise ouster of CEO Sam Altman and ended with Altman being hired by Microsoft. In a letter obtained by CNN, the more than 500 employees accused the OpenAI board of mishandling Altman’s firing, failing to provide sufficient evidence for claims that Altman had not been candid with the board, and “negotiating in bad faith” with the company’s executive leadership. “Your actions have made it obvious that you are incapable of overseeing OpenAI,” wrote the employees. “We are unable to work for or with people that lack competence, judgement and care for our mission and employees.” The employees also warned that they would “imminently” follow Altman to Microsoft unless the board resigns and reinstates Altman and Greg Brockman, the former OpenAI president who was also removed by the board on Friday. Among the signatories is Mira Murati, who as recently as Friday had been named by the board as Altman’s interim successor, as well as Ilya Sutskever, OpenAI’s co-founder, chief scientist and board member who had been widely reported as having played a role in Altman’s dismissal. Murati’s promotion has since been superseded by the appointment of incoming interim CEO Emmett Shear, the 40-year-old co-founder of the livestreaming company Twitch. On Monday, as news of the letter emerged, Sutskever posted an apology on X that acknowledged his contribution to the leadership crisis, which appeared to revolve around tensions between Altman and the board about the pace and scope of AI development. “I deeply regret my participation in the board’s actions,” he said. “I never intended to harm OpenAI. I love everything we’ve built together and I will do everything I can to reunite the company.” The letter highlights the internal divides at OpenAI that have burst into public view after Altman’s firing, and raises further doubts about the fate of OpenAI’s three non-employee board members. That list includes Quora CEO Adam D’Angelo, technology entrepreneur Tasha McCauley and Helen Toner, director of strategy and foundational research grants at Georgetown University’s Center for Security and Emerging Technology. As they sought to manage the fallout of Altman’s firing, the letter claimed, members of the board “informed the leadership team that allowing the company to be destroyed ‘would be consistent with the mission’” of OpenAI, which is to “ensure that artificial general intelligence benefits all of humanity.” The rebuke by some of OpenAI’s most senior employees also underscores Altman’s loyal following and Microsoft’s opportunity to benefit from the situation. “Microsoft has assured us that there are positions for all OpenAI employees,” the letter added. After Sutskever posted his message to X, Altman amplified the apology by quote-posting it. He added a short commentary consisting of three heart emojis. This story has been updated with additional information.