The House of Representatives by a wide margin passed a bill that would make it illegal to distribute or host TikTok in the U.S. — effectively blocking it from some 170 million American users — unless Chinese owner ByteDance divests its interest in the popular app.

It’s the first time a congressional bill has passed that would outlaw an internet app. The fears among many American lawmakers, who see TikTok as a national security threat: that the Chinese regime could demand access to data on TikTok’s U.S. users or somehow compel it to promote China’s agenda.

TikTok has repeatedly claimed the Chinese government has never made such demands (and that TikTok would not comply with them if they were made).

The bill, dubbed the “Protecting Americans From Foreign Adversary Controlled Applications Act,” passed the House by a vote of 352-65 Wednesday morning with bipartisan support, amid pushback from some representatives on both sides of the aisle.

That came after the bill was fast-tracked on a “suspension of the rules” schedule requiring a two-thirds majority to pass. While it had a groundswell of backing in the House, the measure’s fate in the Senate is unclear as there is currently no corresponding legislation on the table.

President Biden has said he would sign the bill if it reaches his desk — even as his re-election campaign just launched an account on TikTok, @bidenhq, last month on Super Bowl Sunday. Biden in 2022 approved a measure banning TikTok on most U.S. government devices.

If signed into law, the legislation is expected to face legal challenges, including potentially from TikTok. Prior attempts in the U.S. to ban TikTok have so far failed on First Amendment grounds and because courts found legal challenges have presented only hypothetical national security risks instead of actual evidence TikTok has shared any data with Chinese authorities.

The threat of an American TikTok ban would escalate tensions between the U.S. and China. Chinese officials have said the government would “firmly oppose” any forced sale of TikTok because it would “seriously undermine the confidence of investors from various countries, including China, to invest in the United States.”

According to China’s commerce ministry, ByteDance’s sale of its TikTok ownership would represent a technology export and be subject to the government’s approval. “You’re not going to be able to force ByteDance to divest,” James Lewis, SVP at the Center for Strategic and International Studies, told the New York Times.

The bill was introduced on March 5 by Rep. Mike Gallagher (R-Wis.) and Rep. Raja Krishnamoorthi (D-Ill.), and was unanimously approved by a House committee in a 50-0 vote. Under the bill, Apple and Google’s app stores and web hosting services in the U.S. would be barred from hosting any “foreign adversary controlled application,” specifically calling out ByteDance’s TikTok, per the text of the bill (H.R. 7521).

The ban would go into effect unless such a “foreign adversary” (i.e. ByteDance) divests its ownership in the app (i.e. TikTok) within 165 days of becoming law. In addition, the bill gives the U.S. president latitude to determine which apps controlled by hostile foreign governments should be subject to the divestiture requirement.

“This is my message to TikTok: break up with the Chinese Communist Party or lose access to your American users,” Gallagher, who is chairman of the House Select Committee on the Strategic Competition Between the United States and the Chinese Communist Party, said in introducing the bill.

Violators of the TikTok ban would face steep fines, amounting to $5,000 multiplied by every U.S. user “determined to have accessed, maintained or updated a foreign adversary controlled application.”

A TikTok rep said in a statement after the vote, “This process was secret and the bill was jammed through for one reason: It’s a ban based on zero evidence. We are hopeful that the Senate will consider the facts, listen to their constituents, and realize the impact on the economy, 7 million small businesses, and the 170 million Americans who use our service.”

Prior to the House vote, Chinese foreign ministry spokesperson Wang Wenbin called the legislative action “bullying behaviour” that “damages the normal international economic and trade order,” per a BBC report. “In the end, this will inevitably come back to bite the United States itself.”

On Tuesday, TikTok sent another in-app alert to users in the U.S. urging them to call their congressional reps to voice their opposition to the bill, after issuing a similar one before last week’s House committee vote.

“Your voice can help the TikTok communities you love,” the message said, similar to another one it sent last week. It let users search their ZIP code to get a phone number for their local representative. Some House members cited TikTok’s mobilization of users in its lobbying campaign as illustrative of its power — and a clear reason the bill should become law.

TikTok has repeatedly insisted that it is no way controlled or owned by the Chinese Communist Party or any other governmental entity. About 60% of ByteDance is owned by “global institutional investors” including BlackRock, General Atlantic, Susquehanna International Group and Sequoia, with 20% owned by the company’s Chinese founders and 20% owned by other employees, according to TikTok.

At a House committee hearing last year, TikTok CEO Shou Zi Chew asserted that forcing ByteDance to divest its ownership stake in the app would not change how TikTok operates. “A change in ownership would not impose any new restrictions on data flows or access,” he said. “All global companies face common challenges that need to be addressed through safeguards and transparency.”

In the Senate, Sen. Chuck Schumer (D-N.Y.), the majority leader, has not committed to bringing a TikTok ban bill to a vote. In addition, Sen. Rand Paul (R-Ky.) told the Washington Post he will block any measure he believes is unconstitutional. “I don’t think Congress should be trying to take away the First Amendment rights of [170] million Americans,” Paul said.

Meanwhile, Donald Trump, who as president unsuccessfully tried to force ByteDance to sell majority control in TikTok to U.S. owners, has weighed in on the current effort to block TikTok or for its Chinese owners to sell their stake in the app.

Last week, he posted on Truth Social, “If you get rid of TikTok, Facebook and Zuckerschmuck will double their business,” calling Facebook “a true Enemy of the People!” In a CNBC interview on Monday, Trump agreed that TikTok’s Chinese ties represent “a national security risk” but reiterated his point that a U.S. government ban on the app would only help Facebook.

“Frankly, there are a lot of people on TikTok that love it. There are a lot of young kids on TikTok who will go crazy without it,” Trump said on CNBC. “There are a lot of users. There’s a lot of good and there’s a lot of bad with TikTok. But the thing I don’t like is that without TikTok, you can make Facebook bigger and I consider Facebook to be an enemy of the people along with a lot of the media.”