A bipartisan effort to stabilize the U.S. health-insurance markets collapsed last month after anti-abortion groups appealed directly to Vice President Mike Pence at the 11th hour, The Daily Beast has learned.

Amid opposition from conservatives in the House of Representatives, a group of pro-life activists met with Pence to lobby the Trump administration against supporting a health-insurance market-stabilization bill on the grounds that it does not contain sufficient language on abortion restrictions, according to sources with direct knowledge of the meeting. Senate Majority Leader Mitch McConnell (R-KY) was also in attendance at the Dec. 19 meeting, three of the sources said.

The next day, key lawmakers involved in crafting the legislation announced they were punting on the issue until 2018.

A spokeswoman for the vice president confirmed the meeting to The Daily Beast. A spokesman for McConnell did not respond to requests for comment.

Efforts to pressure Pence, a hardline social conservative and a former lawmaker, are thrusting abortion back onto the national stage in a debate over the future of health care in America, as Republicans deliberate behind closed doors on whether to try to scrap Obamacare again in 2018.

That effort—though it failed in the Senate several times last year—was bolstered when the House and Senate passed a sweeping tax-overhaul bill last month. The legislation included a provision that scrapped the Obamacare individual mandate, a measure that required Americans to buy health insurance or pay a penalty.

The tax bill passed the Senate due in large part to Sen. Susan Collins’ (R-ME) vote, which was contingent upon the Senate voting at a later date on the bipartisan health-insurance market-stabilization bill that was crafted by Sens. Lamar Alexander (R-TN) and Patty Murray (D-WA). Collins has argued that the legislation would mitigate the effects of the individual-mandate repeal, which the Congressional Budget Office said would result in 13 million more Americans without insurance over the next 10 years. Collins also pushed for her bill with Sen. Bill Nelson (D-FL) that would allocate $10.5 billion for a federal reinsurance pool.

The Alexander-Murray legislation would restore Obamacare subsidies that the Trump administration cut off in October, and it would give individual states more flexibility to set insurance regulations. The Republican proponents of the bill argue that it would serve as a short-term stabilization measure to transition away from the Affordable Care Act, assuming congressional Republicans can come to—or even seek—an agreement on a replacement.

The bill, though, has an unclear path forward. It was thought to have enough support to pass the Senate, but Democrats appear to be backing off the bill, blaming the GOP’s elimination of the individual mandate.

“The Republicans want the bill. My question is, with the change in the marketplace that they created with the tax bill, is it still going to work? We don’t have the answer,” Murray, the co-creator of the compromise bill, told The Daily Beast. “The marketplace has changed dramatically. So we’re looking at it.”

Even before the individual mandate was repealed as part of the tax bill, Alexander-Murray did not pass muster with House Republicans, who last month floated the idea of adding a provision on the Hyde Amendment, which prevents federal dollars from being used for abortions. The pro-life activists who met with Pence last month said the absence of such a measure in the Alexander-Murray bill is a major red flag because it means that the subsidies, known as cost-sharing reduction (CSR) payments, could be used on health plans that fund abortions.

Marjorie Dannenfelser, the president of the pro-life Susan B. Anthony List, wrote in a letter to lawmakers last month that supporting Alexander-Murray is a vote “to directly appropriate taxpayer dollars for insurance that includes abortion.” Dannenfelser attended the meeting with Pence, which was viewed as critical because President Donald Trump had expressed support for Alexander-Murray in closed-door meetings on Capitol Hill, according to senators who attended those meetings.

Supporters of the legislation note that Hyde protections already exist under Obamacare—though pro-life activists claim that those are watered down—and Republican senators pointed to a recent memo from the Centers for Medicare and Medicaid Services stating that the Trump administration would enforce those existing abortion provisions more strictly than the Obama administration did.

Moreover, the law itself only lasts through 2019 as a way to give Republicans enough time to come up with an Obamacare replacement. Still, social conservatives are seeking to further codify those protections so that they could outlast the Trump administration.

Adding Hyde Amendment language would shore up conservative support in the House, where Alexander-Murray has faced stiff opposition from hardliners who argue that the legislation simply props up Obamacare. At the same time, though, such a change to the legislation—which was already brokered in a way that gave concessions to both sides—would nearly eliminate Democratic support for the bill, tanking it altogether.

McConnell’s attendance at the meeting was notable because he, at the urging of Alexander and Collins, delayed a vote on Alexander-Murray until after the holiday recess after initially promising Collins a vote on the bill in December. Republicans were considering adding Alexander-Murray to the government-funding bill before lawmakers left for the holidays, but such a move would have given House Republicans a reason to vote against the short-term funding measure, thereby threatening a government shutdown just three days before Christmas.

The day after the Pence meeting, Collins and Alexander announced they were urging McConnell to punt on the issue until January.

But as congressional leaders continue to negotiate a two-year government funding bill and an immigration deal, health care is expected to take a back seat even as talks continue. Lawmakers must come to an agreement on a funding mechanism before Jan. 19 in order to keep the government’s lights on.

—Betsy Woodruff contributed reporting.