The Biden administration on Monday urged the Supreme Court to leave in place a moratorium on evictions in parts of the country ravaged by the coronavirus pandemic, saying it is a “lawful and urgently needed response to an unprecedented public emergency.”

A coalition of landlords and real estate trade groups in Alabama and Georgia are challenging the latest moratorium imposed by the Centers for Disease Control and Prevention, issued Aug. 3 and intended to run through Oct. 3.

“Congress never gave the CDC the staggering amount of power it claims,” the groups said in a brief filed Friday night with the justices, asking them to block the latest version of the moratorium.

There is reason to think the high court might agree. In June, the justices on a narrow vote left a previous version of the eviction ban in place, when it was supposed to expire at the end of July. Justice Brett M. Kavanaugh, who cast the deciding vote, said he thought the ban should be allowed to wind down.

But he added that he believed CDC lacked authority, and that congressional action would be needed to impose a new moratorium.

Congress did not act, though, and initially the Biden administration said its hands were tied. After pressure from constituent groups and liberals in Congress, one of whom camped out to draw attention to the issue, the administration issued a new and slightly narrowed version of the plan. But even the president was skeptical it would last.

“I went ahead and did it,” Biden told reporters. “But here’s the deal: I can’t guarantee you the court won’t rule [that] we don’t have that authority. But at least we’ll have the ability, if we have to appeal, to keep this going for a month at least — I hope longer than that.”

The challengers told the court that was a cynical response it should not tolerate.

Unless the court halts the moratorium, “Congress will know that it can legislate through pressure campaigns and sit-ins rather than bicameralism and presentment, the Executive Branch will know that it can disregard the views of a majority of Justices with impunity, and this Court will know that its carefully considered rulings will be roundly ignored,” the brief states.

In fact, the court’s June 29 order was a little more opaque. When deciding on requests to stay a lower court’s ruling, the justices often do not explain their reasoning. The four most conservative justices said they would have ended the moratorium, but did not say why. But it seems likely they, like Kavanaugh, thought the CDC exceeded it authority.

In Monday’s filing, acting solicitor general Brian H. Fletcher said the rise of the delta variant has made conditions much different from when the court looked at the issue in June, and showed why it was important for the CDC to be able to respond quickly to changing conditions.

“The fact that more than 80% of the Nation’s counties have been hit hard by COVID-19 … shows that the recent surge in the pandemic is serious and that the threat to which the CDC must respond is widespread,” Fletcher wrote.

The ban on evictions applies to renters who “otherwise would likely need to move to congregate [or shared-living] settings where COVID spreads quickly and easily, or would be rendered homeless and forced into shelters or other settings that would increase their susceptibility to COVID,” the CDC says.

Congress originally imposed an eviction moratorium. When it expired, President Donald Trump ordered the CDC to impose one, which has been extended several times.

The legal issue involves the Public Health Service Act. It gives the agency authority to “make and enforce such regulations … necessary to prevent the introduction, transmission, or spread of communicable diseases” across states or from foreign lands.

But challengers, and some lower courts who have reviewed the issue, say the power is limited by another provision. It lists measures such as “fumigation, disinfection, sanitation, pest extermination, destruction of animals or articles found to be so infected or contaminated as to be sources of dangerous infection to human beings, and other measures, as in his judgment may be necessary.”

To the challengers, that means the CDC is finding its broad authority in a “rarely used statute from 1944 whose domain has previously been limited to matters such as the sale of baby turtles.”

They say the CDC is claiming “unqualified power to take any measure imaginable to stop the spread of any communicable disease — common cold included — whether it be eviction moratoria, worship limits, nationwide lockdowns, school closures, or vaccine mandates.”

Fletcher said the court need not decide every instance in which the CDC’s authority is valid to conclude that this one is.

He said Congress recognized the CDC’s authority at one point by extending the agency’s moratorium, rather than issuing one of its own, and appropriating nearly $47 billion to pay landlords whose tenants are in arrears.

Fletcher likened the moratorium to a quarantine.

“It would be strange to hold that the government may combat infection by prohibiting the tenant from leaving his home, but not by prohibiting the landlord from throwing him out.” he wrote.

While the challengers repeatedly quote Biden and other administration officials saying that the court’s June order made another extension of the CDC moratorium impossible, Fletcher downplayed the comments.

“Those statements are best understood as an acknowledgment that, at least as things stood on June 29, it appeared likely that five Justices would have voted to vacate the stay [imposed by a lower court] if the original moratorium had been extended past July 31,” he wrote.

“The Executive Branch does not defy the rule of law by adopting a policy that it reasonably believes to be a lawful and urgently needed response to an unprecedented public emergency, even if there are indications that this Court may ultimately disagree.”

The case is Alabama Association of Realtors v. Department of Health and Human Services. The court could act on the matter at any time.