The Trump administration faces a midday deadline on Tuesday to provide details about planeloads of Venezuelans it deported despite a judge issuing a temporary ban on removing them.
U.S. Justice Department lawyers must by noon Eastern Time (1600 GMT) answer questions posed by U.S. District Judge James Boasberg surrounding the flights to El Salvador and regarding the proclamation that President Donald Trump issued to justify removing them from the country under a 1798 law.
Trump's lawyers have argued the court's authority on the matter was limited, fueling concerns about Trump further pushing the boundaries of executive power and setting up a potential constitutional clash with the judiciary.
The U.S. Justice Department on Monday sought to remove Boasberg from the case.
The government has also raised national security concerns about answering the judge's questions, suggesting at least part of its response may remain sealed.
The controversy began with Trump's proclamation published on Saturday invoking the Alien Enemies Act of 1798 to declare that the Venezuelan prison gang Tren de Aragua was conducting irregular warfare against the U.S.
The Trump administration claimed those being deported were members of the gang and began removing them on Saturday night, before the judge ordered that any flight be halted or returned to the United States.
Tren de Aragua is a feared criminal organization that trafficks in humans in South America, but despite Trump's claim the group was invading the United States, there has been little documented evidence of any large-scale U.S. operation.
DETAILS SOUGHT
The judge is asking government lawyers to clarify exactly when Trump's proclamation was published, when it took effect, and how many people subject to it were taken into custody. He wants assurances that nobody was deported based solely on the proclamation.
The judge is also seeking details about when the flights took off.
A third flight took off at 7:37 p.m., or 12 minutes after the judge's written order was published. The Trump team has said the third flight carried deportees processed under other immigration authorities beyond the Alien Enemies Act and therefore not subject to the order.
In any event, all three flights, which each made a preliminary stop in Honduras, landed in El Salvador late Saturday night or Sunday morning Eastern Time, hours after the judge's oral and written rulings.
When Boasberg asked for information, some of it available on public flight-tracking sites, Justice Department lawyer Abhishek Kambli told the judge the Trump administration was resistant to sharing information because there was "a lot of operational national security and foreign relations at risk."
Relatives of suspected deportees were desperate to know what happened to their loved ones.
The American Civil Liberties Union, which filed the request that led Boasberg to impose a two-week halt to deportations, also wants to learn more about who was deported and under what circumstances.
ACLU lawyer Lee Gelernt raised the idea of whether the Trump administration's defiance could trigger a constitutional crisis, and he further questioned Trump's assertion that the deported immigrants belonged to Tren de Aragua.
"This has been a habit of the Trump administration to overstate the danger of the people they've arrested," he said.
