Supreme Court justices sounded skeptical Tuesday about imposing new restrictions on the dispensing of abortion drugs through pharmacies or by mail.

The justices, both conservative and liberal, questioned why a group of anti-abortion doctors has legal standing to challenge the Food & Drug Administration’s dispensing rules. That issue, and not the safety of mifepristone, dominated the two-hour discussion, likely a telling sign of what the justices thought about the case.

“The court must put an end to this case,” said Solicitor General Elizabeth B. Prelogar, representing the Biden administration. A handful of doctors who oppose all abortions have no right to challenge the legal use of the drugs by millions of women, she argued.

Only Justice Samuel A. Alito directly challenged the suggestion that the anti-abortion claim should be dismissed. “Is there no one who can dispute this?” he asked.

Conservative Justices Neil M. Gorsuch and Amy Coney Barrett asked only procedural questions.

Barrett said the law already provides “conscience protections” to shield doctors who have moral objections to abortions from being required to perform them. She said she saw no evidence that these protections were not being enforced.

The FDA approved the use of mifepristone in 2000, saying it was safe and effective when combined with a second drug, misoprostol. More than five million women in the U.S. have used the pills since then, the FDA says, and they are now the most common abortion method in this country. In 2016, the FDA relaxed restrictions on how the drug can be prescribed.

The frequency of use has made the drugs a target for anti-abortion activists. Two years ago, shortly after the court struck down the constitutional right to abortion, a group of anti-abortion doctors filed suit in Amarillo, Texas.

They asked for an injunction that would reverse the FDA’s approval of the drugs. And they were looking for a judge who would positively assess their claim. U.S. District Judge Matthew Kacsmaryk, a Trump appointee and the only federal judge based in Amarillo, has “suspended” the FDA’s approval of mifepristone and given the government seven days to appeal his decision.

The U.S. 5th Circuit Court of Appeals decided it was too late to overturn the drug’s approval by the FDA, but agreed to set aside regulations the FDA has adopted since 2016.

Lawyers for the Biden administration appealed to the Supreme Court, and the justices voted to stay the case. Justices Alito and Clarence Thomas dissented.