Three Democratic senators are urging President Donald Trump to work with Congress to save TikTok from going dark in the US after April 5th, rather than plow ahead with plans that could leave TikTok’s service providers open to hundreds of billions of dollars in liability.

Sens. Ed Markey (D-MA), Chris Van Hollen (D-MD), and Cory Booker (D-NJ) say they oppose the TikTok ban, which was passed by Congress in an overwhelming vote last year and required the app’s Chinese parent company ByteDance to divest it by January 19th or face an effective expulsion. But, they write in a letter to Trump, “it is unacceptable and unworkable for your Administration to continue ignoring the requirements in the law, as you did in January by extending the divestment deadline to April 5.”

The law punishes service providers that work with TikTok after the divestment deadline, leaving them open to up to $850 billion in liability. Trump — who was the original proponent of a TikTok ban in his first term, before billing himself as its savior during his most recent campaign — signed an executive order on his first day back in office promising not to enforce the ban for 75 days.

This was always a legally shaky plan, experts told The Verge. For one thing, the ban deadline had technically passed by the time Trump was sworn into office, even though former President Joe Biden effectively punted the ball to him in his final days in the White House. The law has an extension mechanism that the president can employ to extend the deadline 90 days if a sale is underway, but neither Biden nor Trump tried to use that, and the 75 day extension by executive order is something entirely different.

The order can’t override the law itself, and even if service providers like Oracle, Apple and Google take Trump at his word that his Justice Department won’t enforce the law against them, the statute of limitations extends past his term limit. That said, it’s not clear how much that will constrain Trump’s actions — congressional Republicans have so far mostly avoided criticizing Trump (though at least one has warned him against a weak deal), and in a separate case, Trump has suggested that a judge that disagrees with him should be impeached.

The senators charge that Trump’s 75-day extension was “unlawful” and its effectiveness in keeping TikTok operating in the US ultimately relies on the “risk tolerance” of TikTok’s service providers. While some of TikTok’s service providers, including Oracle, were willing to trust Trump’s promise of legal safety, others, like Apple and Google, held off on returning it to their app stores until reportedly receiving a letter from Attorney General Pam Bondi assuring them the law wouldn’t be enforced against them.

Trump seems to be weighing two options to keep TikTok running past April 5th: extending the deadline or cutting a deal to bring TikTok into compliance with the law. One proposal before the Trump administration, Bloomberg reported based on unnamed sources, would involve Oracle providing assurances that US user data was safe from Chinese government access, but letting the app’s recommendation algorithm remain with ByteDance. The arrangement appears similar to Project Texas, a proposed TikTok-Oracle partnership that lawmakers and officials rejected as inadequate to resolve concerns.

Rep. John Moolenaar (R-MI), who chairs the House Select Committee on China, has warned that under the law, “ByteDance must fully divest its control of TikTok and have no say in its operations; nor can the two share data, content, or algorithms. These are non-negotiable, and any deal that doesn’t meet these requirements simply isn’t legal.”

But the senators warn that in either case, the reported approaches Trump is considering would leave TikTok’s service providers exposed to potentially crushing liability. “To the extent that you continue trying to delay the divestment deadline through executive orders, any further extensions of the TikTok deadline will require Oracle, Apple, Google, and other companies to continue risking ruinous legal liability, a difficult decision to justify in perpetuity,” they write. “On the other hand, if your Administration works to complete a deal with Oracle — under which Oracle would reportedly take a small stake in TikTok and provide certainty about the security of TikTok’s user data — such a deal would almost certainly not satisfy the Act’s requirements around a qualified divestiture.”

The lawmakers propose an alternative: “Work with Congress.” They urge Trump to ask Senate Republicans to pass the “Extend the TikTok Deadline Act” — a bill Markey proposed shortly before Trump’s inauguration, before the ban took place, to give the company until October to complete a sale.

If Trump is set on moving forward with an Oracle partnership instead of a full sale, the lawmakers urge him to work with Congress to modify the original law to ensure TikTok can still legally operate. “Regardless of your approach, the path to saving TikTok should run through Capitol Hill,” they write.