Federal appeals court judges heard arguments Wednesday on a stringent Texas abortion law that critics say would shutter more than half the state's remaining abortion clinics, and asked pointed questions of attorneys for both sides.

In the closely watched case, a three-judge panel of the 5th U.S. Circuit Court of Appeals in New Orleans is weighing a requirement that the state's abortion clinics must meet certain hospital-like standards for care, equipment and staffing. The law, known as HB2, had been voided by a lower court last year.

At the core of the court's inquiry is whether the law poses an "undue burden" on women who seek an abortion — the standard established by the 1992 Supreme Court in Planned Parenthood v. Casey.

Before Texas passed abortion restrictions in 2013, there were 40 licensed abortion facilities in the state. That number has since dropped by more than half, with advocates saying that number would be reduced to eight, at most, if the ambulatory surgical center requirement takes effect.

Critics of the law say that its restrictive provisions — which include the requirement that abortion practitioners have admitting privileges at a hospital within 30 miles of the clinic — are aimed at making it difficult for women to access abortions.

Judge Catharina Haynes said she was troubled by the law's effective requirement that clinics be at least 7,000 square feet large. While questioning the plaintiff's counsel, she also expressed concern about the broadness of the lower court's ruling striking down the size requirements together with other, more minor provisions, such as those covering soap dispensers.

"Why can't you have a sterile environment in a 3,000-foot [facility]?" she asked Texas Solicitor General Jonathan Mitchell, who argued that the law was designed to reduce complications and improve patient care.

Both Haynes and Judge Jennifer Elrod asked Mitchell whether women in McAllen and El Paso would, under Texas law, have adequate access to abortion, a line of questioning abortion-rights advocates took as hopeful in a case they expect to lose in the conservative-leaning appeals court.

"They appear to take seriously the undue burden faced by women in El Paso and McAllen," said Amy Hagstrom Miller, founder of Whole Woman's Health, a plaintiff in the suit.

No matter the ruling, the losing side is expected to appeal to the U.S. Supreme Court.

In his August ruling striking down HB2, U.S. District Judge Lee Yeakel lifted the restrictions on admitting privileges in two regions, McAllen and El Paso, saying they were forcing women in those areas to travel hundreds of miles for an abortion.

The 5th Circuit said on Oct. 2 that Texas could begin fully enforcing the law. Later that month, the U.S. Supreme Court ordered that Yeakel's decision remain in effect, sending the case back to the 5th Circuit.

Al Jazeera and Reuters