Tesla boss Elon Musk has ordered staff to return to the office full-time, declaring that working remotely is no longer acceptable.
The new policy was shared in emails that were leaked to social media.
Tesla did not respond to a request for comment on the messages, one of which appeared to be addressed to executives.
People who are unwilling to abide by the new rules can “pretend to work somewhere else” Mr Musk said on Twitter, when asked about the policy.
“Everyone at Tesla is required to spend a minimum of 40 hours in the office per week,” he wrote in one of the emails. “If you don’t show up, we will assume you have resigned.”