The Senate on Monday brought a bill to codify same-sex marriage protections one step closer to passage, voting to end debate on an amendment that features religious liberty protections sought by Republicans.

The process wasn’t without hiccups, however.

Senators ultimately voted 61-35 to advance the amendment to the Respect for Marriage Act that includes language related to religious liberty and conscience protections under the Constitution and federal law. It would also continues to prohibit polygamous marriage.

But the voting was held open for almost two-and-a-half hours as senators wrangled over whether additional amendments could come up for a vote and waited on the votes of three Republicans who had earlier this month voted to advance the broader bill. Sixty votes were needed to limit debate.

According to the time agreement struck, votes on three amendments proposed by Sens. Mike Lee (R-Utah), James Lankford (R-Okla.) and Marco Rubio (R-Fla.) will be held on Tuesday afternoon, with a vote on final passage expected to take place immediately following. The vote series will start at 3:45 p.m.

Lee’s amendment will need 60 votes to be attached, while Lankford’s and Rubio’s will each need a simple majority of senators to win inclusion on the final bill. All three are aimed at protecting religious liberty amid concerns that an amendment negotiated that is already attached to the legislation does not go far enough to protect religious entities. 

Sen. Thom Tillis (R-N.C.), a leading GOP proponent of the Respect for Marriage Act, told reporters after the deal was struck that while he supports Lee’s amendment, it is “far more expansive” than the narrow bill that negotiators cobbled together. 

“I think one of the things that make it very difficult for getting people to come to an agreement is just giving everyone the Heisman instead of listening to them and trying to give them an opportunity to get a vote. I’ve got no problem with it,” Tillis said. “I wish we’d do more amendment votes around here. It was an earnest effort on our part to let them have their amendments be heard and let the vote go where the vote goes tomorrow.” 

Monday’s vote puts lawmakers another step closer to sending the bill to President Biden’s desk. The measure has already passed the House, but because of the narrow amendment it would have to go back to the lower chamber for another vote. The House passed the bill in July with the support of 47 Republicans.

The absence of Sen. Raphael Warnock (D-Ga.), who is competing in a runoff election on Dec. 6, also complicated the path to 60 votes. Ultimately, all 12 GOP senators who voted earlier this month to advance the measure voted in the affirmative Monday: Susan Collins (Maine), Rob Portman (Ohio), Mitt Romney (Utah), Lisa Murkowski (Alaska), Roy Blunt (Mo.), Richard Burr (N.C.), Cynthia Lummis (Wyo.), Shelley Moore Capito (W.Va.), Dan Sullivan (Alaska), Joni Ernst (Iowa), Todd Young (Ind.) and Tillis. 

“We all know that for all the progress that we’ve made on same-sex marriage, the rights of all married couples will never truly be safe without the proper protections under federal law, and that’s why the Respect for Marriage Act is necessary,” Senate Majority Leader Charles Schumer (D-N.Y.) said on the Senate floor on Monday.

Some Republicans who supported the measure have received blowback for backing the legislation. More than 40 Christian leaders called on Lummis to “reverse course” and change her vote unless the final version includes Lee’s amendment.

“[The bill] labels people of good faith as bigots and subjects them to endless harassing litigation and discrimination and threats by that same government that was founded to protect their religious liberty,” Lee said on the Senate floor before the Thanksgiving recess. “We need to protect religious freedom. This bill doesn’t do that. It places it in grave jeopardy.”

Updated at 8:44 p.m.