One senator’s opposition to LGBT rights could indefinitely shut down the Equal Employment Opportunity Commission come 2019.

And the only person who can stop that from happening is Mitch McConnell.

Because Sen. Mike Lee (R-UT) has publicly stated that he will not vote for a slate of Trump EEOC nominees that includes Chai Feldblum—an out lesbian whom Lee has accused of trying “to undermine our nation’s founding principles”—it’s unlikely that the Senate will be able to fill the seats required to keep the EEOC fully operational.

In other words, at the end of the current legislative session, the federal agency tasked with enforcing civil rights law in the workplace—including LGBT protections—will be unable to do so until enough commissioners are appointed or reappointed.

The only way to stop that from happening would be for Mitch McConnell to bring the matter before the full Senate for a vote—but the probability of that happening before midnight on New Year’s Eve is low. (“It’s not likely McConnell will extend the session for this,” one anonymous congressional staffer told NBC News.)

LGBT leaders are calling for Sen. McConnell to recognize the urgency of the situation.

“Americans need a fully functional EEOC to combat discrimination and sexual harassment in the workplace, and Mike Lee’s anti-LGBTQ views should not stand in the way of those seeking justice under the law,” Zeke Stokes, GLAAD’s vice president of programs, told The Daily Beast. “Majority Leader Mitch McConnell should abide by set precedent and immediately hold a full Senate vote on the EEOC nominees, where fair-minded voices will prevail.”

As Vox reported, Democratic Senators believe enough Republican senators would join them in voting for Feldblum and the other EEOC nominees—but McConnell would have to bring the matter before the Senate by 2019.

Sen. McConnell’s office did not immediately respond to The Daily Beast’s request for comment.

Trump’s December 2017 re-appointment of Feldblum, a former Georgetown professor who has served on the EEOC since 2010, has long been an object of ire for social conservatives and anti-LGBT groups, as The Atlantic reported in April.

Those groups see Feldblum as a radical threat to “religious liberty” based on her support of same-sex marriage rights and her efforts to include sexual orientation and gender identity in non-discrimination law.

Asked about Sen. Lee’s opposition to Feldblum’s confirmation, a spokesperson told The Daily Beast that she held “extreme views on the use of government power to crush religious minorities.”

Sen. Lee’s office also pointed to a speech he gave two weeks ago in which he depicts Feldblum as hostile to religious rights.

Feldblum herself responded to Sen. Lee’s speech in a Medium post last week, alleging that the quotes in his speech “were either misconstrued or taken out of context.” She explained that she believes full compliance with non-discrimination laws should be mandatory for employers whether or not they are owned by “religious individuals”—but that this is a separate issue from the matter of religious organizations.

“During the confirmation process, I asked Senator Lee several times to meet with me so he could hear my views directly,” Feldblum wrote. “He chose not to do [so]. It is unfortunate that I did not have the opportunity to explain to Senator Lee how the quotes he was using failed to capture my full position.”

This is not the first time that the Trump administration has angered anti-LGBT groups. Despite widespread efforts to roll back LGBT rights, Trump has angered anti-LGBT groups for allowing openly gay diplomat Randy Berry to continue serving and for appointing openly lesbian judge Mary M. Rowland.

But as The Atlantic explained, Feldblum is a Trump nominee in name only. Because the EEOC is a bipartisan agency, Republicans get three out of five seats when they are in power while Democrats get two. It is standard procedure, The Atlantic noted, for each party to get EEOC picks fast-tracked through the Senate, circumventing a lengthy confirmation process. Feldblum, in other words, is a Democratic pick that Trump rubber-stamped—but that’s how the EEOC nomination process has typically worked.

If Sen. McConnell doesn’t allow the full Senate to vote on the current EEOC nominees—or if Sen. Lee doesn’t reverse his opposition to Feldblum—the EEOC will be left with just two out of five seats filled—not enough to rule on employment discrimination cases.

That’s especially significant for LGBT people because—even as the White House rolls back protective executive orders and issues anti-LGBT policies—the Equal Employment Opportunity Commission has continued to interpret existing civil rights law as inclusive of gender identity and sexual orientation based on Title VII’s ban on sex discrimination.

In fact, the EEOC currently lists four pending cases in which the commission is fighting for LGBT people who allege that they were discriminated against in a workplace setting, including, for example, a lawsuit against the Bojangles restaurant chain on behalf of a transgender woman who says that she was told to continue dressing as a man.

But hindering the operations of the EEOC would also have far-reaching consequences for any protected class that may need to seek redress from workplace discrimination and sexual harassment, including women as well as religious and racial minorities.

Minority Leader Schumer did not immediately respond to The Daily Beast’s request for comment on a contingency plan if the Senate does not confirm Feldblum.

The nomination must go through the Health, Education, Labor and Pensions Committee, which is currently chaired by Sen. Lamar Alexander (R-TN).

“Chai Feldblum has been confirmed twice and has the votes to be confirmed again,” Senator Patty Murray (D-WA), a ranking member of that committee, wrote on Twitter. “I’m calling for Senator Lee to drop his ridiculous objection and allow the EEOC to continue its essential work.”