A rapidly advancing proposal from members of Congress could present one of the biggest threats yet to TikTok’s future in the US.

Bipartisan legislation from the House of Representatives would force the China-based platform to sell off a controlling share or face removal from US app stores.

House Republicans have proposed bringing the bill to the floor for a vote as soon as this week, though it’s unclear whether a similar proposal can survive the Democratically controlled Senate, which has yet to produce any kind of companion legislation.

However, in recent days, President Joe Biden and his Republican rival Donald Trump have each weighed in, throwing a political wrench into TikTok’s future in the middle of an election year.

The president has signalled that he would sign the legislation into law, while Mr Trump appears to have reversed his position and now suggests that he would not support a measure that could effectively ban TikTok in the US.

Their opposition could tee up a significant political question as millions of young Americans, including eight million newly eligible young voters, prepare to cast their ballots in the 2024 elections.

If signed into law, the Protecting Americans from Foreign Adversary Controlled Applications Act – co-authored by a group of Republican lawmakers investigating the Chinese Communist Party – would allow federal law enforcement agencies to list certain apps as national security threats if they are determined to be under the control of foreign adversaries.

Those apps would then be banned from US app stores unless they sever ties with those entities within 180 days.

The measure follows pressure from members of Congress and officials across the US to force TikTok’s parent company ByteDance to divest from the app over questions about whether China is using TikTok to harvest US user data. Lawmakers have also accused TikTok of negatively impacting young people’s mental health.

ByteDance would be compelled to sell all but 20 per cent of its TikTok stake to a US-based company to keep operating in the country.

On 7 March, a House committee advanced the bill on a rare unanimous bipartisan vote of 50-0, even as TikTok users flooded congressional lines with thousands of calls urging lawmakers to back off.

That same day, the former president wrote on his Truth Social that “if you get rid of TikTok, Facebook and Zuckerschmuck will double their business,” referring to Meta CEO Mark Zuckerberg.

“I don’t want Facebook, who cheated in the last Election, doing better,” wrote Mr Trump, echoing a baseless conspiracy theory that social media platforms rigged elections against him. “They are a true Enemy of the People!”

The former president’s latest statements mark a reversal of his previous support for banning the app. He now says that he would have banned the app during his presidency but instead left it up to Congress.

“I was at the point where I could have gotten it done if I wanted to,” he told MSNBC’s Squawk Box on 11 March. “I should have said, you guys decide, you make that decision, because there are a lot of people who talk that love it … There are a lot of young kids on TikTok who will go crazy without it. There are a lot of users.”

In 2020, Mr Trump issued an executive order banning TikTok that the company successfully challenged in court. His administration pushed for Microsoft to acquire the app, while the company partnered with software company Oracle to protect US user data.

The reasons for his reversal aren’t clear, though he recently spoke at a conference for influential right-wing group Club for Growth at the request of a GOP megadonor Jeff Yass, who has a $20bn stake in ByteDance.

Club for Growth, which Mr Trump previously blasted as “Club for No Growth”, is largely expected to spend millions of dollars in the 2024 election cycle to support the GOP’s nominee to face against Mr Biden.

A massive injection into his campaign would be a major relief against a tidal wave of costly legal obligations, including nearly half a billion dollars owed to New York after he was found liable for fraud, and tens of millions of dollars owed to his legal teams mounting their defence in four criminal cases and a growing list of lawsuits.

President Biden, meanwhile, told reporters on 8 March that if Congress passes the bill, “I’ll sign it.”

His administration banned TikTok from federal government devices, though his re-election campaign joined the app in February.

The legislation also has the support of the Biden administration’s Federal Communications Commission, whose commissioner accused TikTok of “engaging in a pattern of illicit surveillance and making false statements about personnel in Beijing accessing sensitive US user data”.

“TikTok’s own conduct makes clear that it is beholden to the CCP and presents an unacceptable threat to US national security,” according to Commissioner Brendan Carr.

The video app “cannot continue to operate in the US in its current form”, he added.

Former Democratic House speaker Nancy Pelosi told The Independent that she feels “pretty good” about the full House passing the measure on 13 March.

Federal law enforcement agencies and lawmakers from both parties, as well as Mr Trump, have argued that TikTok presents a national security threat. Officials have argued that the Chinese government is using or could use TikTok to mine data from its millions of users and show content that could warp users’ views, particularly surrounding information designed to manipulate the outcome of 2024 elections.

The Biden administration has previously supported an alternate Democratic-led proposal in the Senate that would aim to tackle national security concerns about TikTok without trampling Americans’ First Amendment rights.

Several Republican-led states have banned TikTok from government devices, while the state of Montana banned the app altogether, though that law was blocked in federal court.

Last week, a message on the app warned users that the US government “will take away the community that you and millions of other Americans love” and called for support to avert a TikTok “shutdown”.

“This will damage millions of businesses, destroy the livelihoods of countless creators across the country, and deny artists an audience,” the message read. “Let Congress know what TikTok means to you and tell them to vote NO. Call now.”

In a letter to TikTok CEO Shou Zi Chew on 11 March, House Reps Mike Gallagher and Raja Krishnamoorthi demanded the company “stop spreading false claims in its campaign to manipulate and mobilize American citizens on behalf of the Chinese Communist Party”.

“These messages are deceptive,” they wrote. “All TikTok would have to do is separate from CCP-controlled ByteDance. However, if TikTok chose not to rid itself of this CCP control, the application would no longer be offered in US app stores. But TikTok would have no one but itself to blame – it would be choosing this path by opting for CCP control rather than Americans’ privacy and national security.”

The bill gives TikTok “a simple choice”, according to Mr Gallagher, a Republican co-chair of the House Select Committee on the CCP. “Either side with its users… and allow people to speak free from the fear of propaganda or censorship, or side with the Chinese Communist Party.”