Billionaire Elon Musk issued an ultimatum to federal employees Saturday, saying in a post on his social media platform X that employees must respond to an email justifying the work they completed this week or resign. Federal employees have already began receiving the email, sources familiar with the matter told NBC News.

Federal workers began receiving emails Saturday asking them to explain what work they did last week, as Elon Musk announced that “failure to respond will be taken as a resignation.”

Hundreds of thousands of federal workers have little more than 48 hours to explain what they accomplished over the last week