AMARILLO, United States, March 16, 2023 (BSS/AFP) - A US federal judge with longstanding ties to conservative religious groups questioned Wednesday the unprecedented nature of a suit asking him to issue a national ban on a widely used abortion pill.

However, during a high-stakes hearing in his Texas courtroom, Judge Matthew Kacsmaryk appeared sympathetic to some of the arguments put forward by plaintiffs targeting prescription drug mifepristone, according to the few reporters allowed inside to observe the tightly restricted proceedings.

The suit against the Food and Drug Administration is the latest step in the campaign to win a total ban on abortion following a landmark Supreme Court ruling last year. It takes aim at a pill involved in 53 percent of all abortions in the United States, or more than half a million every year.

While the FDA has never been challenged like this before on its approval of a drug that has proven safe and effective, the plaintiffs -- a coalition of anti-abortion groups -- believe they can win a national freeze on distribution of mifepristone.

Reproductive rights activists who were briefed on Wednesday's hearing from someone who listened in acknowledged the real possibility the judge will order the drug be taken off the market.

"We can expect the worst and I think we need to be prepared for that," Wendy Davis, a senior advisor to Planned Parenthood Texas Votes, told reporters.

Presiding over the case in federal court in Amarillo, Texas is Kacsmaryk, who was appointed to the bench by Republican former president Donald Trump and confirmed by the Senate in 2019.

The judge is a conservative Christian with a personal history of opposition to abortion and a court record of favoring right-wing causes.

The case landed in his court via what critics call "judge-shopping," in which plaintiffs take legal action in a district where the judge has a history of rulings that support their case.

Federal judges in the United States have a right to issue rulings that carry national legal force.

- 'Concerns' despite safety record -

It is not clear when Kacsmaryk will make his decision, but if he rules in favor of the plaintiffs, the US government is widely expected to appeal.

A small group of protesters gathered outside the courthouse Wednesday, carrying signs bearing slogans such as, "Not your uterus, not your decision."

Lindsay London, a 41-year-old nurse, said the case was "100 percent ideologically based."

"If they were concerned about people's health there would be many other actions they would be taking. It's ideological, not based in science."

A handful of supporters of the suit also appeared, including Rita Cantu Hernandez, a Christian minister who knelt and wept.

"I was praying against the abortion pill because there's some concerns about... how unsafe it is," she said.

One component of a two-drug regimen used for medication abortion, mifepristone can be used in the United States through the first 10 weeks of pregnancy.

It has a long safety record, and the FDA estimates 5.6 million Americans have used it to terminate pregnancies since it was approved.

But the Alliance Defending Freedom, a conservative Christian advocacy group, sued the FDA, saying the approval of mifepristone "disavow(ed)" science, "ignored" potential health impacts and "disregarded" the complications that can arise with its use.

"The FDA failed America's women and girls when it chose politics over science and approved chemical abortion drugs for use in the United States," they said.

The FDA has urged the judge to reject the request.

"The public interest would be dramatically harmed by effectively withdrawing from the marketplace a safe and effective drug that has lawfully been on the market for 22 years," it said.

In the hearing, plaintiffs urged Kacsmaryk to act swiftly, either through suspending or withdrawing the medication. Attorney Erik Baptist said the harms of such drugs "know no bounds" and "time cannot be lost," according to a CNN reporter.

- Banned in some states -

Some 15 states already restrict access to mifepristone by requiring a physician to provide it, according to the Guttmacher Institute, a reproductive health policy and research group.

Abortion care has halted in another 13 states after the Supreme Court overturned the long-established constitutional right last June.

The Texas suit seeks to block mifepristone nationally by overturning FDA approval of the drug, and asks Kacsmaryk to first suspend the approval via injunction -- an effective ban -- while the lawsuit proceeds through his court.

Abortion rights groups say a ruling blocking mifepristone would be as consequential as the Supreme Court's ruling last year.

"Access to medication abortion would end across the country -- even in those states where abortion rights are protected," the Center for Reproductive Rights said.