Pennsylvania Republican Sen. Pat Toomey is raising concerns about a key piece of the House’s emergency coronavirus bill, suggesting it might need changes before it can pass the upper chamber.

Toomey worries that a requirement for paid medical and family leave for companies with fewer than 500 employees could be too expensive for small businesses.

“It could, if not designed properly, impose a cost on small businesses that could put them under and it would be, of course, a terrible mistake to have legislation that would have the unintended consequence of wiping out who knows how many millions of jobs across the country by bankrupting small businesses,” Toomey said in an interview Monday evening.

He suggested the House bill could be significantly altered when the Senate takes it up, likely this week, though that’s a process that could delay final approval of the measure. “It’s entirely possible that what we vote on on the Senate floor won’t be that bill,” Toomey said.

Toomey said he has raised his concerns with Treasury Secretary Steve Mnuchin, who negotiated the bill with House Speaker Nancy Pelosi. One option, Toomey said, could be to expand unemployment insurance to support workers, instead of relying on paid leave to support them. That would put more costs on the government, not the businesses.

“I support the goal of the bill,” and relief to workers, Toomey said. “I want to do it in a fashion that doesn’t destroy jobs.”

President Donald Trump has publicly supported the measure that passed the House. But Toomey, a fiscal conservative who once ran a sports bar in the Allentown area, is one of a number of Republicans raising concerns about the paid leave provision.

The House bill, which is still awaiting some corrections and final House approval, provides tax credits to help businesses cover the cost of the paid leave. But Toomey said many businesses might not have enough money in reserve to wait for the credits to arrive.

Republicans have long criticized family leave plans for the costs they could impose on businesses. Democrats argue that the proposal is especially important now, as workers are encouraged or forced to stay home to quarantine themselves, care for children sent home from school, or care for sick loved ones.