A ban on TikTok is tucked into the 4,155-page federal spending bill that Congress is expected to pass this week.
The ban would apply to all executive agency employees. There are exceptions for law enforcement, national security interests and security researchers.
The revolt against TikTok comes as numerous states ban the app from government devices, citing security concerns.
The platform is run by ByteDance, a company based in China. Lawmakers claim it has to answer to the government and could be used to monitor or manipulate Americans.
TikTok has defended its record, saying U.S. user data is stored safely outside of China.
Lawmakers are working to pass the 2023 $1.7 trillion omnibus bill before the weekend to avoid a government shutdown.