College students and abortion rights activists hold a rally in Feruary at the Texas Capitol in Austin. The Supreme Court refused on June 29 to allow Texas to enforce restrictions that would force 10 abortion clinics to close. (Eric Gay/AP)

The Supreme Court barred Texas on Monday from implementing a law that would have forced more than half the state’s 19 abortion clinics to close their doors this week.

The law, which was to take effect Wednesday, would require clinics to adhere to strict new physical standards and the doctors who perform abortions to have admitting privileges at local hospitals.

The court granted the reprieve after abortion rights groups requested an emergency stay, having unsuccessfully sought to have the law overturned. The stay will probably remain in place at least through the summer while the parties assemble a legal case and the court decides whether to take it up in the next term.

The court did not offer a reason for its 5-to-4 decision, and the law’s ultimate fate remains unclear. The court’s reliably conservative justices — Antonin Scalia, Clarence Thomas, Samuel A. Alito and Chief Justice John G. Roberts Jr. — dissented and would have let the law take effect.

The court hasn’t considered the abortion issue since 2007, when it upheld a federal ban on what some call “partial-birth” abortions. But a recent wave of state-level restrictions has put fresh pressure on the court to scrutinize limits placed on the procedure, which remains legal but is increasingly difficult to obtain in some states.

In particular, the court may be called upon to clarify what constitutes an “undue burden” on a woman seeking an abortion. The court set that standard for new state restrictions in 1992, when it refused to overturn Roe v. Wade, the landmark ruling that legalized abortion nationally.

The decision to temporarily block the Texas restrictions prompted a sigh of relief from abortion rights groups and clinic operators, who said they had been prepared for clinic closures across a broad swath of the state. They contend that the new state standards are medically unnecessary and that the law’s real purpose is to reduce access to abortion.

With the court’s decision Monday, they warned that their fight is not over.

“This Supreme Court decision is a temporary victory for Texans’ health and safety, but it only postpones a public health disaster,” Heather Busby, executive director of NARAL Pro-Choice Texas, said in a statement. “The reality is that Texans’ health and safety are still in jeopardy.”

Texas Republican leaders immediately criticized the decision, arguing that the new restrictions are intended to safeguard women’s health. Attorney General Ken Paxton (R), who also sharply criticized the court’s decision last week legalizing same-sex marriage, said in a statement that the justices “just put Texas women in harm’s way.”

Gov. Greg Abbott (R) expressed confidence that the law would survive the legal challenge.

“Texas will continue to fight for higher-quality healthcare standards for women while protecting our most vulnerable — the unborn — and I’m confident the Supreme Court will ultimately uphold this law,” he said in a statement.

The law in question is House Bill 2, a sweeping measure approved two years ago that instituted an array of abortion restrictions that activists say are already responsible for the closing of half the state’s abortion clinics. The provisions blocked Monday were the final parts of that law awaiting implementation.

Beginning Wednesday, doctors performing abortions would have been required to have special relationships with hospitals within 30 miles of their abortion clinics. Supporters of the “admitting-privileges rule” say it ensures that a patient is able to receive lifesaving care in case her abortion goes awry.

Critics say these privileges are virtually impossible for many abortion providers to obtain, in part because abortions are so safe. Doctors who perform them are therefore generally unable to attain the minimum number of admissions most hospitals require to establish such a relationship.

Another part of the law would require abortion clinics to have the same equipment and facilities standards of outpatient surgical centers. Supporters of the law say imposing those standards would make such important changes as ensuring that hallways are wide enough for hospital gurneys.

But opponents of the law say such standards are not necessary, either for surgical abortions or for abortions induced by medication. Meanwhile, such upgrades would be impossible for many clinics, either financially or physically, abortion rights groups say — forcing them to shut down.