A federal judge scheduled an unusual Sunday morning hearing to decide whether the US can go through with its ban on the video-sharing app TikTok. ByteDance, TikTok’s Chinese owner, has asked the court to block the ban, set to begin on Sunday night, even as it pursues approvals from the government for the sale of a stake in its US operations to Oracle Corp. and Walmart under pressure from President Donald Trump. Mr Trump cited national security last month in announcing a ban on the widely used network from US app stores. The president, who has also barred WeChat, owned by China’s Tencent Holdings, has told ByteDance its only alternative is to sell its American TikTok business. The Justice Department argues that the apps could allow China’s government to gain access to the personal data of millions of Americans. On Friday the government emphasised those concerns to the judge in a filing, urging him not to grant the temporary block. US lawyers cited the FBI director’s assessment that the People’s Republic of China – or PRC – poses the “greatest long-term threat to our nation’s information and intellectual property” as a reason for the ban. “One of the tools that the PRC uses to further its goals is bulk data collection,” the US government said. ByteDance, founded in 2012 by Zhang Yiming, has close ties to the Chinese Communist Party and must abide by laws that require it to cooperate with China’s government, the US said. The ban, announced in an August 6 executive order, is part of a wider effort by the administration to take a hard line against Beijing, as Mr Trump bets it will help him win re-election. Starting at 11:59pm on September 27, it would remove TikTok from the app stores run by Apple and Google’s Android, the most widely used marketplaces for downloadable apps. People who don’t yet have the app wouldn’t be able to get it, and those who already have it wouldn’t have access to updates needed to ensure its safe and smooth operation. TikTok is used regularly by 19 million Americans. Ahead of the looming deadline, ByteDance had argued for an expedited schedule in the case. The US pushed back at a hearing on Thursday, saying ByteDance had filed a separate suit more than a month ago and was late in requesting the injunction in this one. In defence of the ban, the government again cited security concerns. “TikTok is allowed to continue operating with respect to existing users but cannot add users, and the reason for that is that there are significant national security risks,” Assistant US Attorney Daniel Schwei told the judge. TikTok said that the ban was already undermining its business model by scaring users away and that it had sought relief as soon as it was allowed to under the law. It said the government would have argued its request was premature if filed earlier. “The urgency of this is created by the Sunday night ban,” attorney John Hall said. “That part of it makes absolutely no sense to us.” Mr Hall told the judge the ban would increase risks to existing users by preventing them from getting regular security updates. He said the deadline was affecting the company’s reputation with users, who are considering moving to less attractive platforms. In the social media industry, Mr Hall said, “users retained is absolutely the lifeblood of their business”.