UPDATED, June 25, 7:15 p.m.: SB 353 passed the senate with a vote of 32 to 13, and will be sent to the governor for signature.

UPDATED, June 25, 2:20 p.m.: SB 353 has been removed from the senate rules committee and placed directly on the senate supplemental calendar, which suggests that a senate vote to concur could occur at any point during Thursday’s session.

North Carolina’s SB 353, a motorcycle safety bill that includes some of the most restrictive anti-choice amendments the state has ever seen, has been idling in the senate rules committee since last week. Thursday is listed as the last day of the state’s legislative session, but under state rules the proceedings could go on well beyond midnight, potentially giving anti-choice legislators enough time to pass the bill late Thursday night or Friday morning—an outcome pro-choice and anti-choice advocates alike are preparing themselves for.

SB 353 includes a version of the anti-choice amendments that were originally included in an anti-Sharia law bill, among them bans on sex-selective abortions, coverage for abortion care in the state health insurance exchange, and telemedicine abortions, as well as a rule requiring the state health department to hold abortion clinics to the same standards as ambulatory surgical centers, which could result in many clinic closures.

By the time the legislative session adjourns, the rules committee must either review the bill and consider sending it to the full senate for concurrence, or let it die until the next legislative session in May 2014. Advocates on both sides of the debate are unsure which path the committee will take, but they agree that it is likely to be a long night. Unlike in Texas, where the final day of the legislative session ends at midnight sharp, North Carolina lawmakers can continue to meet until they officially adjourn, signaling the end of the legislative session. That means it is more difficult in North Carolina to run down the clock.

“The Senate will go into session at 11:00 am and be in session until the wee hours of Friday morning. (They will be recessing at various times during this period.),” North Carolina Right to Life told its supporters on Facebook. “We do not know when they will vote to concur on SB353, our pro-life omnibus bill, but we assume that it will be sometime before they adjourn on Friday morning because they will be going home, not to return until mid-May 2014.”

As Matt Binker writes on his blog at WRAL.com, there’s an “intriguing possibility that one of the most high-profile, controversial bills of the session could pass—if it passes—in the wee hours of the morning when very few people are watching the process.”

In many ways, that would be an appropriate ending for abortion restrictions that were proposed using maneuvers meant to keep public input to a minimum at nearly every turn; the measures were first a part of the Sharia law bill, then the motorcycle safety bill, and they were primarily debated in committees and during floor votes with so little advance warning that often legislators themselves didn’t know what was in the bills until minutes before the meeting.

Pro-choice advocates in the state say they’re in it for the long haul Thursday night. “SB 353 is the most devastating attack on reproductive rights we’ve seen in decades,” Suzanne Buckley, executive director of NARAL Pro-Choice North Carolina, told Rewire. “Thousands of activists from NARAL Pro-Choice NC and other groups have demonstrated at Moral Monday, attending hearings and contacted their lawmakers in opposition to the bill. We remain vigilant in our fight against SB 353. Any movement on this bill—whether in the light of day or cover of darkness—will be remembered in 2014.”