After narrowly passing the House on Wednesday, a bill that would grant seven days of paid sick time to railway workers faces a difficult battle in the Senate.

After labor unions and railroad companies couldn’t agree on better benefits for workers, the Biden administration spent months trying to prevent a strike. Eighteen of the 12 unions agreed to a tentative agreement which increased pay by 24%, secured bonuses, and paid sick leave. However this was a sticking point that ultimately stalled negotiations.

On Tuesday, Speaker Nancy Pelosi (D-CA), announced that the House would vote for labor unions to adhere to the agreement. President Joe Biden had called for Congress to act. This prompted pushback from progressive members, who insisted that workers deserve better than the one-day of paid sick time in the legislation.

Senator Bernie Sanders (I-VT), pledged to stop the tentative agreement from moving forward if better sick leaves were not up for a vote.

Pelosi declared Tuesday night that a separate vote would take place that would, if approved, grant workers the seven-day leave they need. The House passed the tentative agreement quickly the next morning. However, the sick days measure was barely approved.

Only three House Republicans voted in favor of the paid leave bill, indicating that it will struggle to pass the upper chamber. There are 60 votes required to defeat a filibuster.

The legislation will be considered by the Senate as soon as possible, possibly as early as Thursday.

A few senator Republicans showed sympathy for rail workers and said that their demands were understandable.

“The demands from the rail workers on their face seem quite reasonable,” Ted Cruz (Republican-Texas) said to reporters Tuesday, before Pelosi announced a separate vote regarding paid sick leave. “And so, I am skeptical of the Democrats efforts to reject reasonable demands that the rail workers have made.”

Cruz’s comments are similar to those made by Sens. Marco Rubio (R–FL) and Josh Hawley, both Republicans from Missouri, criticized Biden’s insistence on Congress governing the labor unions.

Many Republicans are wary of government intervention in private industry and are reluctant to intervene in the labor dispute. It’s also unclear if 10 Republicans support the paid leave. This assumes that all 50 Democrats vote yes. Joe Manchin, a centrist Democrat from West Virginia, says he isn’t sure about the addition of paid sick day.

John Thune, Minority Whip (Republican-State of Delaware), told the Washington Examiner that it was “hard to know” if the GOP votes were there. He admitted that the conference was divided.

He said that there are members who are — I’d argue that we have many different views and opinions about the subject. These range from “This isn’t something Congress should do in the first place” to “This is the right thing to do in the second place.”

Multiple senators said that it is not the job of Congress to criticize the labor agreement.

“Congress’s role in approving a rail settlement is to approve it, not to help with negotiations.” “You don’t need 535 arbitrators negotiating the details for a labor agreement,” Senator Kevin Cramer (R.ND) stated Wednesday.

Hawley stated that he would reject the tentative agreement, but vote for the seven-days of paid sick time. Cruz declined to support the paid sick leave provision when Cruz was asked Wednesday if he would.

Sanders joined 11 other Democratic senators to call for the Senate’s swift passage of the lower chamber’s legislation after the House bills were passed.

“We thank President Biden for his hard work and Labor Secretary Walsh’s willingness to negotiate a tentative agreement that is more favorable than the terrible proposal from the rail industry. They stated that Congress could and should improve this agreement.