The Biden administration is asking the Supreme Court to block the Texas law banning most abortions, while the fight over the measure's constitutionality plays out in the courts.

The law has been in effect since September, aside from a district court-ordered pause that lasted just 48 hours, and bans abortions once cardiac activity is detected, usually around six weeks and before some women know they are pregnant.

The Justice Department asked the high court Monday to lift an order imposed by a conservative federal appeals court that has allowed Texas to continue enforcing the nation's strictest curbs on abortion through a novel law that was written to make it hard to challenge in the federal court system. The department had announced its intentions last Friday.

The Texas law defies the Supreme Court's major decisions on abortion rights “by banning abortion long before viability -- indeed, before many women even realize they are pregnant,” the Justice Department wrote in its plea to the court.

“The question now is whether Texas’ nullification of this Court’s precedents should be allowed to continue while the courts consider the United States’ suit. As the district court recognized, it should not,” the Justice Department wrote.

The administration also raised the prospect that the court could decide to grant full review to the Texas law and rule on its constitutionality this term, even though lower courts have yet to do so. The Supreme Court rarely steps in this early in a lawsuit.

The Texas law and the possibility that other states could adopt similar measures justify the court's early involvement, the administration said.

The high court ordered Texas to respond by midday Thursday.

It's not clear whether the administration will prevail at a Supreme Court with a conservative majority that has been fortified by three appointees of former President Donald Trump and already has agreed to hear a major challenge to abortion rights in a case from Mississippi.

The Trump appointees, joined by two other conservatives, have once before rejected a plea to keep the law on hold, in a separate lawsuit filed by abortion providers. There was no immediate timetable for Supreme Court action on this latest motion.

While courts have blocked other state laws effectively banning abortion before a fetus can survive outside the womb, roughly around 24 weeks, the Texas law has so far avoided a similar fate because of its unique structure that leaves enforcement up to private citizens, rather than state officials. Anyone who brings a successful lawsuit against an abortion provider for violating the law is entitled to claim at least $10,000 in damages.

In the 5-4 vote last month to allow the law to remain in effect, the high court acknowledged in an unsigned order that there were “serious questions regarding the constitutionality of the Texas law” but also “complex and novel” procedural questions about whom to sue and whether federal courts had the power to stop the law from being enforced.

In a dissenting opinion, Chief Justice John Roberts wrote that he would have put the “unprecedented” law on hold so that court could consider “whether a state can avoid responsibility for its laws” by handing off enforcement. The court’s three liberal justices also dissented.

The question now is whether the administration’s presence in the new lawsuit will make a difference. A three-judge panel of the 5th U.S. Circuit Court of Appeals provided its answer late Thursday, extending its earlier order that allows the law to remain in effect. In a 2-1 vote, the court said it was siding with Texas for the same reasons the Supreme Court and a different 5th Circuit panel cited in the providers’ lawsuit — questioning whether anyone could march into federal court to challenge the law.

Texas sought help from the appeals court after U.S. District Judge Robert Pitman ruled that the Justice Department did have the ability to sue and that he had the authority to stop the law from being enforced, writing that “women have been unlawfully prevented from exercising control over their lives in ways that are protected by the Constitution.”

The judge conceded, however, that “other courts may find a way to avoid this conclusion.”