The prospect of the Senate quickly passing the $2 trillion coronavirus relief deal that congressional leaders struck with the White House hit a speed bump Wednesday after a group of Republican senators demanded an amendment related to unemployment insurance.

The state of play: Republican Sens. Lindsey Graham (S.C.), Tim Scott (S.C.), Ben Sasse (Neb.) and Rick Scott (Fla.) said Wednesday that they would object to fast-tracking the bill over a provision that would grant an extra $600 per week in unemployment benefits to low-wage workers who lose their jobs.

The Republican senators argue that because the unemployment benefits would be larger than what low-wage workers usually make, it would incentivize them to get laid off and not return to the workforce.

The amendment they want to introduce would limit unemployment benefits to 100% of a worker's salary.

The other side: Sen. Bernie Sanders later released a statement saying that unless the senators drop their "anti-worker objections," he is prepared to block the legislation in order to impose "strong conditions on the $500 billion corporate welfare fund."

“I am prepared to put a hold on this bill … to make sure that any corporation receiving financial assistance under this legislation does not lay off workers, cut wages or benefits, ship jobs overseas, or pay workers poverty wages," Sanders said.

Sanders told the New York Times that he will vote for the bill as written, but only if the Republicans drop their demands: "I cannot at the last minute allow some right-wing senators try to undermine the needs of workers and think they are going to get away with that.”

The big picture: The stock market lost a ton of steam after news broke of a potential holdup of the aid package.