The US supreme court has agreed to hear a challenge to one of the nation’s harshest abortion laws in what could be the most consequential case on abortion rights the court has taken in 23 years.

The law, known as HB2, is a Texas measure passed in 2013 that has since led to the closure of more than half the state’s abortion clinics. Out of the hundreds of new abortion restrictions lawmakers have passed since 2010, few have had such a profound impact on abortion access in a single state.

“This law is causing real harm to women across the state of Texas,” said Amy Hagstrom Miller, the founder of Whole Woman’s Health, a network of abortion clinics with four locations in Texas. “We have been fighting this draconian law since 2013 … I am hopeful that the supreme court will uphold the rights that have been in place for four decades and reaffirm that every woman should be able to make her own decision about continuing or ending a pregnancy.”

Whole Woman’s Health is one of several providers suing to overturn the law.

Before the law began to take effect, Texas had 41 abortion clinics. A provision requiring abortion providers to have admitting privileges with a hospital cut that number in half, and there are 18 clinics today. A second provision of the law, which has been blocked on and off for two years, would further slash the number of providers to nine or 10. That provision mandates that all abortion clinics comply with hospital-like “ambulatory surgical center” standards, which are too expensive for most abortion providers to meet.

The stakes of the case are enormous. Texas abortion providers are challenging the supreme court to declare how far states can go in restricting abortion ostensibly to protect women’s health, which the court has never fully clarified.

In a 1992 case, Planned Parenthood v Casey, the supreme court gave states the right to restrict abortion in the interest of the woman’s health as long as the restriction is not an “undue burden”. But the court has never defined what the term means.

Abortion foes contend that a law is not an undue burden unless it takes a major toll on abortion access, while abortion rights advocates argue that a law is an undue burden if it serves no actual medical purpose. Which argument prevails could make the difference between a tidal wave of anti-abortion bills and a trickle. Conservative state lawmakers have enacted hundreds of new abortion restrictions in the past five years that mainstream medical organizations say carry no real health benefits.

“I don’t think it’s overstating the case to say if the court upholds the restrictions based on the justifications each state is offering – that these are health protective – that it would result in the most drastic reduction of the availability of abortion at any point since Roe v Wade,” Priscilla Smith, director of Yale Law School’s reproductive justice program, said last week.

A sweeping opinion on the Texas law would have immediate consequences for abortion clinics in seven other states. Alabama, Kansas, Louisiana, Mississippi, Oklahoma, Tennessee and Wisconsin have all passed similar laws, now mired in legal battles, which could close a combined 20 abortion clinics. Several of those states would be left with just one or two abortion providers.

A favorable ruling for abortion foes could also drive new restrictions. “If the supreme court gives the thumbs-up to these types of regulations, you will see other states follow,” said Denise Burke, vice-president of legal affairs of Americans United for Life, which supported the Texas measure. Other anti-abortion proposals, such as those restricting when and where women may use medication to end their pregnancies, may also benefit from a ruling for Texas or Mississippi.

The court on Friday did not say whether it would hear another appeal from Mississippi to enforce a harsh 2012 abortion measure. The case presents a similar constitutional question, and could be addressed by a broad ruling in the Texas case.

The Mississippi law required physicians performing abortions to have admitting privileges at a local hospital, which the state touted as a safety measure. Abortion foes derided the measure as unnecessary for patient safety and a poorly disguised attempt to shut down the state’s only clinic, the Jackson Women’s Health Organization.

Under the law, Mississippi would have become the first state without a single abortion provider since the court established the right to abortion in Roe v Wade almost 43 years ago. The fifth circuit court of appeals blocked that law in 2014.

A three-panel judge drawn from the same circuit upheld the Texas law in June. The court’s four liberal justices plus justice Anthony Kennedy temporarily blocked that decision from going into effect and closing down all but nine or 10 Texas abortion clinics. The abortion providers appealed to the supreme court in early September.

Abortion rights advocates argue that ambulatory surgical center and admitting privilege requirements are not necessary to perform safe abortions and do not make abortion safer. They see ASCs, which can cost an abortion provider millions of dollars to build and maintain, as a way of putting abortion providers out of business.

“ASC and privileges requirements do nothing to protect the health and safety of women and are incongruous with modern medical practice,” read a brief submitted to the fifth circuit by the American College of Obstetricians and Gynecologists and the American Medical Association. “Scientific literature suggests that the safety of abortions performed in an office setting is equivalent to the safety of those performed in a hospital setting … HB2’s requirement that abortion facilities meet the standards for ASCs is devoid of any medical or scientific purpose.”

The brief noted that most abortions are simple procedures, with no incisions, and the risk of death from abortion is 0.0006%, while only 0.05%-0.2% of abortion procedures involve major complications.

Texas is a state with 5.4 million women of reproductive age. With only a handful of clinics left, researchers have estimated that nearly 2 million women would live more than 50 miles from the nearest abortion clinic. Three-quarters of a million women would live more than 200 miles away. And because wait times for an abortion would skyrocket, the number of second-trimester procedures, which are more expensive, invasive and time-intensive, could double.