The Justice Department told the Supreme Court on Tuesday that the Biden administration’s plans to let COVID-19 public health emergencies expire in May would make it unnecessary for the justices to decide a case related to a pandemic-era border expulsion policy.

In a filing, the DOJ said that expiration would also mean the end of the so-called Title 42 border policy, in place since March 2020, which allows border agents to rapidly expel migrants who cross the border without considering their asylum claims.

The end of the border policy — which is at the center of the high court case — “would render this case moot,” the Justice Department lawyers wrote.

Given that, the government said it would be “appropriate” for the Supreme Court to send the case back down to the lower court for it to be dismissed.

As it stands, the Supreme Court has agreed to decide whether a group of Republican-led states may join a lawsuit in Washington and defend the border rule from a legal challenge. Earlier in the case, a district court judge found that the border policy was issued illegally and ordered it terminated.

If the justices decide to let the states join the case, it could tee up further battles in the lower courts over the legality of the border rule. Oral argument is scheduled for March 1, and a decision would be expected by the conclusion of the term at the end of June.

The government’s position, which it also told a federal appeals court Monday in separate related litigation, marks the latest ripple in the ongoing legal saga over the Title 42 border policy.

House Republicans have contested the Biden administration’s assertion that the end of the public health emergency would mean the Title 42 policy would have to end.

The policy has been sharply criticized by human rights advocates, who say the restrictions flout the nation’s obligations to asylum-seekers. Congressional Republicans say the administration is not enforcing the restrictions enough.

The Biden administration has also maintained inconsistent positions on the border policy, at times criticizing the policy for fueling repeat border crossings, while also expanding its usage to expel migrants from additional countries.

The Centers for Disease Control and Prevention attempted to end the directive last year after determining that pandemic conditions had improved, but a Louisiana federal judge blocked that effort in a separate lawsuit brought by Republican-led states.

Still, the Justice Department has continued to defend its right to implement the policy in court. In the lawsuit in Washington, the Biden administration appealed the ruling to end the Title 42 policy but did not request to keep it in place while the appeal continued.

That prompted a group of Republican-led states to ask to join the case and defend the Title 42 policy in the government’s stead, nearly two years after the suit was filed. A federal appeals court rebuffed their request, but the Supreme Court paused the court-ordered end of the Title 42 policy as it considers the case.

In Tuesday’s brief, the Justice Department also urged the high court to find that the states’ request to join the case came too late. The DOJ also noted that the state’s arguments center on immigration-related consequences of lifting the border policy, even though the directive is rooted in a public health statute.

“By their own account, therefore, petitioners’ interest in keeping the Title 42 orders in place is to vindicate asserted interests in controlling immigration — not in protecting public health,” the government said.

The DOJ also warned that a ruling allowing the states to intervene in the case would “radically transform litigation in suits involving the government.”

If the court were to allow the states to intervene, it could “flood the courts with motions for emergency relief from States and other parties claiming to be injured by the indirect effects of district-court judgments,” the government argued.