The future of Twitter seemed to hang in the balance after its offices closed on Friday and its key employees announced they were leaving despite an ultimatum from new owner Elon Musk. Fears have grown that the new outlet will threaten the existence of one of the world’s most influential internet platforms, an important communication tool for the world’s media, politicians, companies and celebrities.

Musk, who is also the CEO of Tesla and SpaceX, has come under fire for radical changes in the California-based firm he bought less than a month ago for $44 billion. In an internal memo sent this week, Musk told employees that they must choose to be “extremely tough” or lose their jobs.

It has already laid off half of the company’s 7,500 employees, removed the work-from-home policy and implemented long hours, and efforts to revamp Twitter have met with backlash and delays.

“I may be #exceptional, but dammit I’m not #hardcore,” tweeted Andrea Horst, a former employee who still writes “Supply Chain Management & Power (Survivor) @Twitter” on her LinkedIn profile.

Their unsuccessful attempts to overhaul user verification with a controversial subscription service led to a string of fake accounts and sweepstakes, causing major advertisers to withdraw from the platform.

“Not too worried”

According to Musk, heated conversations about the site’s imminent shutdown have generated record interest on Twitter. He drew attention to irony by posting a popular meme of the actor jokingly posing over a tomb. Both the man and the tombstone were covered with the Twitter logo. The post was “liked” by more than 1.3 million users. Twitter CEO Elon Musk said in a note to staff that they should choose “hardcore” or lose their jobs.

In a tweet posted on the West Coast later on Friday morning, the South African-born billionaire said: “A record number of users are signing in to see if Twitter is dead, which ironically makes it more alive than ever!” musk added “The best people stay, so I don’t worry too much”.

Despite Musk’s assurances, Twitter’s offices were temporarily closed until Monday, even with badges, according to an internal memo released to US media. In an internal memo sent Wednesday, Musk asked employees to follow a link to confirm their commitment to the “new Twitter” until 5pm New York time (22:00 GMT) on Thursday.

Otherwise, they will lose their jobs and receive three months’ severance pay. Twitter did not respond to AFP’s request for comment on the new measure. Signs that government regulators were impatient with Musk’s take on Twitter also rose on Friday, particularly over the platform’s ability to manage content with a significantly reduced staff.

A group of US senators said on Thursday that Musk’s plans for the site “undermine the integrity and security of the platform … despite clear warnings that these changes will be used for scams, fraud and dangerous impersonation.” Meanwhile, the European Union’s top regulator said Musk should increase the number of moderators in Europe, not reduce it.

EU Commissioner Thierry Breton said Musk “knows very well what the conditions are for Twitter to continue operating in Europe”. A spokesman for German Chancellor Olaf Scholz said the government was following developments on Twitter “with increasing concern” and was reviewing its presence on the platform.