Supreme Court Justice Sonia Sotomayor granted a last-ditch plea from a Catholic nuns' group Tuesday night to block a birth control mandate in the new health care law just hours before it was to have gone into effect.
Sotomayor issued the stay at the request of the Little Sisters of the Poor Home for the Aged, based in Colorado. They are part of a larger effort by Catholic-affiliated groups from around the nation to halt provisions of the Affordable Care Act that require insurance companies to provide contraceptives free of charge. Employers who offer insurance must take part -- both for-profit and not-for-profit groups.
The groups want the mandate halted while the court considers a legal challenge brought by the Little Sisters and other religious groups. Their challenge is separate from one brought by for-profit company Hobby Lobby and a Pennsylvania woodworking company that says it's against the religious beliefs of the owners to provide birth control.
In June, the 10th U.S. Circuit Court of Appeals in Denver waived millions of dollars of fines against Hobby Lobby and a subsidiary, Mardel Christian Stores, which refused to comply with the mandate, writing that the companies were likely to win their claim that requiring for-profit companies to pay for birth control was a violation of religious protections.
In December, the 10th Circuit refused to waive the requirement for the Little Sisters, noting they are exempt from providing birth control anyway because they are a religious organization.
The motion for a stay went to Sotomayor as the justice with oversight for the 10th Circuit. She gave the government until Friday to respond.
"Tomorrow, a regulatory mandate will expose numerous Catholic organizations to draconian fines unless they abandon their religious convictions and take actions that facilitate access to abortion-inducing products, contraceptives, sterilization, and related education and counseling for their employees," the groups said in their request for a stay Tuesday.
The White House's reaction was muted.
"We defer to the Department of Justice on litigation matters, but remain confident that our final rules strike the balance of providing women with free contraceptive coverage while preventing non-profit religious organizations with religious objections to contraceptive coverage from having to contract, arrange, pay, or refer for such coverage," a White House official told NBC News.
The Obama administration had crafted a compromise, or accommodation, that attempted to create a buffer for religiously affiliated hospitals, universities and social service groups that oppose birth control. The law requires insurers or the health plan’s outside administrator to pay for birth control coverage and creates a way to reimburse them.
But for that to work, the nuns would have to sign a form authorizing their insurance company to provide contraceptive coverage, which would still violate their beliefs, their lawyer Mark L. Rienzi said.
“Without an emergency injunction, Mother Provincial Loraine Marie Maguire has to decide between two courses of action: (a) sign and submit a self-certification form, thereby violating her religious beliefs; or (b) refuse to sign the form and pay ruinous fines,” he said.
Opponents of the mandate praised the action.
"The Obama administration's HHS mandate is an egregious and blatant violation of the religious freedom that Americans have enjoyed for more than 220 years," Senator Roy Blunt, R-Mo., said in a statement. "No American should be forced to surrender their religious freedom or abandon their deeply held religious beliefs. I applaud Justice Sotomayor's move to block this onerous government overreach, which violates Americans' constitutional rights."
NBC News' Shawna Thomas and The Associated Press contributed to this report.
Editor's note: An earlier version of this story stated the Affordable Care Act requires companies to offer health-care coverage that provides abortion-inducing drugs to their employees. It does not.