Elon Musk has scrapped Twitter's work from home policy and ordered its staff back to the office, days after firing 3,700 employees.
The social media platform's new owner told staff in an email, seen by the Guardian, that its "road ahead is arduous and will require intense work to succeed".
The Tesla CEO added that working from home would no longer be allowed except in special circumstances, with such cases personally vetted by Musk.
"Remote work is no longer allowed, unless you have a specific exception. Managers will send the exception lists to me for review and approval," Musk wrote.
He added that the new policy, first reported by Bloomberg, would be effective from Thursday for a minimum of 40 hours a week.
The news comes as the company continues to shed staff. Musk fired about half of the company's 7,500-strong workforce last Friday, having bought it for $44bn (£38.7bn) the previous week, and the chief information security officer, Lea Kissner, confirmed on Thursday she had left Twitter in the latest high-profile departure.
Musk said Twitter had been hit by a pause in spending from advertisers that had caused "a massive drop in revenue". Twitter makes most of its more than $5bn in annual revenue from advertising.
The company has begun rolling out Twitter Blue, its new subscription service, in the UK. Users who pay £6.99 a month get a blue tick next to their username, as well as early access to forthcoming features such as bookmark folders and the ability to change the colour of the app icon. Musk is hoping that Twitter Blue will reduce the company's reliance on advertising.
Despite the chief executive's promise last week that the international pricing of Blue would be adjusted "proportionate to purchasing power parity", an economic measure of exchange rates that takes into account the cost of living in various countries, Musk seems to have given ground to Apple. The subscription service is billed through Apple's in-app purchases, which locked Twitter into charging £6.99 in the UK to match the $7.99 in the US.
Musk tried to reassure advertisers about his plans for the company in a meeting on Twitter's audio chat feature, Spaces, on Wednesday.
Big brands including General Motors, United Airlines, the cereal maker General Mills and others have paused buying ads on Twitter as they watch whether Musk's past comments that he is a "free speech absolutist" will lead to a rise in hate speech and divisive content on the platform.
Brands on Wednesday's call included Deutsche Bank, Chevron, Nissan, Air Canada and Audi, which has paused Twitter ads. The American outdoor equipment retailer REI also attended and said after the call that its ads were still paused, according to Associated Press.
Musk said during the call that he was still planning a moderation council that would tackle inappropriate content and consider account reinstatements, but it would take "a few months" to assemble. He said it would be advisory and "not a command council".
The mass layoffs have raised concern about the company's ability to maintain security on the platform and comply with government regulations. Those fears were compounded this week by the departure of three top security officials at the company, including Kissner, the chief privacy officer, Damien Kieran, and the chief compliance officer, Marianne Fogarty.
In their absence, employees are being encouraged to "self-certify" the platform is running in compliance with privacy laws, according to a report from the Verge on Thursday. Breaking these laws could result in billions of dollars in fines. This comes after Twitter reached a settlement with the Federal Trade Commission in May over privacy issues, under which it is required to perform privacy reviews before making changes to its products. The report suggested Musk had already "bypassed its standard data governance processes" relating to changes, and an internal lawyer told workers to seek whistleblower protection "if you feel uncomfortable about anything you're being asked to do", according to the Verge.
Kari Paul contributed reporting
