The Biden administration is asking the Supreme Court to block the Texas law banning most abortions, while the fight over the measure’s validity 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.

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.