TikTok is facing yet another call from a prominent lawmaker for the app’s ban, Colorado Senator Michael Bennet, a Democrat who sits on the Senate Intelligence Committee, sent a letter to Apple and Google urging the companies to ban TikTok from their respective app stores.

In the letter, Bennet says that “TikTok, in its current form, [is] an unacceptable threat to the national security of the United States.” The letter, addressed to Apple CEO Tim Cook and Google CEO Sundar Pichai, repeats many of the same points that have been raised by other lawmakers seeking to ban the app.

Specifically, Bennet raises the possibility that TikTok’s parent company, ByteDance, could be compelled to “use its influence to advance Chinese government interests,” via TikTok. “Like most social media platforms, TikTok collects vast and sophisticated data from its users, including faceprints and voiceprints,” Bennet writes. “Unlike most social media platforms, TikTok poses a unique concern because Chinese law obligates ByteDance, its Beijing-based parent company, to ‘support, assist, and cooperate with state intelligence work.’”

TikTok has long denied that such scenarios could play out, and has attempted to downplay its ties to China. In a statement to CNN the company said Bennet’s letter “relies almost exclusively on misleading reporting about TikTok, the data we collect, and our data security controls.”

Apple and Google didn’t immediately respond to requests for comment.

While it seems unlikely either company would take such a drastic step based on a letter from one senator, it highlights the mounting pressure and scrutiny on TkTok. The company has spent the last two years negotiating with the Committee on Foreign Investment in the United States (CFIUS) in order to secure its ability to continue to operate in the US. But that process is reportedly stalled, and the company has been waging a new charm offensive in an attempt to win over critics.

TikTok has also been sharing more details around its partnership with Oracle to safeguard US user data and comply with US regulators’ concerns. But lawmakers seem to be in no rush to let TikTok off the hook. The app has already been banned from federal devices, and numerous state governments have passed bans of their own. TikTok CEO Shou Zi Chew is scheduled to testify at his first Congressional hearing next month,