Elon Musk sent a message to Twitter Inc staff telling them they had until Thursday to decide whether they wanted to stay on at the company to work “long hours at high intensity” or take a severance package of three months pay.Musk told Twitter employees that anyone who had not clicked on a link confirming “you want to be part of the new Twitter” by Thursday evening New York time would be considered to have quit.A copy of the message, which was reported by The Washington Post, was reviewed by Reuters. Three sources who had received the message at Twitter confirmed its content.Twitter did not immediately respond to a request for comment from Reuters.The latest move to restructure the company comes after Twitter slashed half of its workforce earlier this month as Musk took control of the social media company. Musk has criticized Twitter’s spending and work culture, and said that the company needs steep cost cuts and a reboot of its services.”Going forward, to build a breakthrough Twitter 2.0 and succeed in an increasingly competitive world, we will need to be extremely hardcore,” the message from Musk said. “This will mean long hours at high intensity. Only exceptional performance will constitute a passing grade.”Musk said Twitter would be “much more engineering-driven” under his leadership, adding that “those writing great code will constitute the majority of our team and have the greatest sway.”The billionaire CEO of Tesla Inc (TSLA.O) has taken to cost cutting with a vengeance. Even after mass layoffs that forced it to attempt to offer some employees in critical divisions to return, some employees on Tuesday said they had been fired, which they suspected was due to posting critical comments of the company or Musk on Twitter or its internal message platform. Musk called himself a “free speech absolutist” when he pursued the Twitter purchase.