Frustrated by the failure of the Republican-controlled Congress to pass any bill repealing any part of the Affordable Care Act, President Donald Trump has threatened to take things into his own hands.

The president has suggested he might cut off billions of dollars in cost sharing reduction payments (CSRs) to health insurance companies, a move that would throw the individual market into chaos and trigger massive hikes in premiums. He has characterized these payments as a “bailout” for insurance companies, but the payments subsidize the cost of insurance for millions of sick and low-income Americans. Even Trump’s suggestion that the payments may end has already wreaked havoc in the insurance market, causing insurers to raise rates or leave certain areas altogether.

Trump’s threat is not finding much support on Capitol Hill, where lawmakers across the political spectrum say the payments must continue—whether they come from the executive branch or are appropriated by Congress. (That is the subject of a pending lawsuit.)

“I hope the president will use his authority to extend those payments,” Sen. John Thune (R-SD), a member of the GOP leadership team, told reporters Monday night. If Trump pulls the trigger and stops the payments, he added, Congress will “look at what our options are” to keep them coming.

Over in the House, moderates like Rep. Charlie Dent (R-PA) and conservatives like Rep. Kevin Brady (R-TX) have raised a similar alarm. A growing, bipartisan group of House members released a proposal on Monday to stabilize the individual market by having Congress appropriate the CSR money, guaranteeing stability by taking the decision out of Trump’s hands altogether.

Correction: The post has been corrected to properly reflect that Sen. Thune represents South Dakota, not Tennessee.