A federal appeals court ruled against the Trump administration on Tuesday, saying it cannot indefinitely detain most immigrants without providing them access to bond hearings.

The unanimous decision from the U.S. Court of Appeals for the Second Circuit marks the first loss at the appellate level for President Donald Trump’s shift to mandatory detention. Other appeals courts have sided with the administration, setting up a potential Supreme Court battle over the policy.

At issue is a July memo from Immigration and Customs Enforcement declaring that any immigrant who entered the country without inspection must be detained under the law. The law had been interpreted for nearly three decades as only mandating the detention without bond of immigrants apprehended at the border. This shift has led to the detention of immigrants who have lived in the U.S. for decades and don’t have criminal records.

The new interpretation of the law “would send a seismic shock through our immigration detention system and society, straining our already overcrowded detention infrastructure, incarcerating millions, separating families, and disrupting communities,” Judge Joseph Bianco, a Trump appointee, wrote for the three-judge panel.

“If Congress meant to achieve such a radical break from the past, it would not have done so in such an indirect and ambiguous way,” Bianco continued.

Judges José Cabranes, a Clinton appointee, and Allison Nathan, a Biden appointee, issued the decision.

A Department of Homeland Security spokesperson said federal court rulings against the policy came from judicial activists.

“President Trump and Secretary Mullin are now enforcing this law as it was actually written to keep America safe,” the spokesperson said.

In recent months, two divided appellate circuits have handed the Trump administration victories on the matter.

“In contrast to past administrations, the current Administration has chosen to exercise a greater portion of its authority by treating applicants for admission under the provision designed to apply to them,” wrote Judge Edith Jones, a Reagan appointee, for the 2-1 majority out of the Fifth Circuit Court of Appeals in February.

Bianco acknowledged the split from the other circuits in the opinion.

“Today, although we part ways with two other circuits that have addressed this question, we join the overwhelming majority of federal judges across the Nation to consider it and conclude that the government’s novel interpretation of the immigration statutes defies their plain text,” he wrote.

This article has been updated to include a comment from the Department of Homeland Security.