WASHINGTON ― The Trump administration is on the verge of rolling back a federal rule that requires most employers to cover birth control in their health insurance plans at no cost to women.

The White House Office of Management and Budget posted on its website that it is reviewing an interim final rule that would allow religious employers to deny contraception coverage to their female employees. The details of the rule have not been announced, but Gretchen Borchelt, the vice president of the National Women’s Law Center, said it is certain that “some women will lose birth control coverage.”

House Minority Leader Nancy Pelosi (D-Calif.) called the move “sickening.”

“The draft rule announced today attempts to tear away women’s control over their own private health decisions and put that control in the hands of employers and politicians,” she said.

The contraception mandate, enacted under President Barack Obama in 2012, for the first time in U.S. history deemed birth control an essential preventive health service that should be fully covered alongside well-woman visits, mammograms and sexually transmitted infection screenings. It guarantees coverage to more than 55 million women, saved women $1.4 billion on birth control pills in the first year it went into effect, and has contributed to the lowest U.S. abortion rate since the procedure became legal in 1973.

Some religious employers have been fighting the mandate since it was announced. The Supreme Court ruled in 2014 that closely held corporations like Hobby Lobby, a Christian-owned craft supply chain, cannot be required to provide contraception coverage for their employees. The Obama administration tried to accommodate those employers by directing them to state their religious objections to the government, which would then direct a third-party insurer to provide the coverage to the organization’s female employees.

Some groups, like an organization of nuns called Little Sisters of the Poor, have continued to challenge the rule. President Donald Trump signed an executive order in March directing the Department of Health and Human Services to re-examine the birth control coverage rule, promising the Little Sisters at the time that their “long ordeal will soon be over.”

HHS Secretary Tom Price, a vocal opponent of reproductive rights, commended Trump for “taking a strong stand for religious liberty.” He had told ThinkProgress in 2012 that no woman has trouble affording her monthly birth control prescriptions.

“Bring me one woman who has been left behind,” he said at the time. “Bring me one. There’s not one. The fact of the matter is, this is a trampling of religious freedom and religious liberty in this country.”

The Center for Reproductive Rights, a legal advocacy group, said it plans to challenge the new rule.

“Without health coverage of contraception under the [Affordable Care Act], countless women will lose their basic right to prevent pregnancy and plan when they have children,” said Nancy Northup, president and chief executive officer of the Center for Reproductive Rights. “Plain and simple: President Trump’s executive order will hurt women. And the Center for Reproductive Rights is ready to fight back in court.”