The legal saga surrounding President Trump’s order to restrict transgender military service took another turn Monday as federal judges lobbed tough questions at opponents in a D.C. courtroom.

The panel of judges on the D.C. Circuit Court of Appeals wanted to know why the judiciary should be involved in deciding who is combat ready and why banning troops who have undergone gender transition surgery is discriminatory.

The oral arguments were part of the Justice Department’s effort to lift one of four court injunctions that have blocked the Trump administration from imposing its new policy barring enlistment for anyone who has undergone gender reassignment surgery or been diagnosed with gender dysphoria.

Judge Thomas Griffith said existing case law suggests the courts should often defer to the government when it comes to who can serve.

“Isn't that what both those cases teach us is to tell courts, 'Tread very carefully if at all here,' because we leave to the political branches the determination of who is combat ready and who is not combat ready?” Griffith said during the arguments. “Why isn't that precisely what we're dealing with here? You are asking the courts to make determinations we are not equipped to make: Who is combat ready, who is not.”

Jennifer Levi, a lead attorney for transgender troops suing the administration, argued against the appeals court lifting the injunction in Washington, D.C., and told the judge that the policy first ordered by Trump in a memo last year was aimed at a group of people and not about combat readiness.

“The weight of the evidence before the district court was that the 2017 White House memorandum was based on discrimination against a class of individuals,” said Levi, who is the director of the Transgender Rights Project for the group GLAD. “And the government was directed to develop an implementation plan to carry out that discriminatory directive.”

The appeals court panel must now render a decision on whether to lift the injunction, which could take weeks or months, and the administration has also petitioned the Supreme Court to hear the transgender ban.

Trump had originally tweeted in July 2017 that transgender troops would no longer be able to serve in any capacity and later issued the order for Defense Secretary Jim Mattis to roll back the open service policy enacted by the Obama administration.

Transgender troops and rights groups immediately sued and have since been waging pitched legal battles with the Justice Department in four states. Mattis studied the issue in the meantime and released his final policy in March that would exclude many transgender people from enlisting but allow nearly 1,000 currently serving to be grandfathered and remain.

Opponents of the ban have been successful so far, and four U.S. district courts have granted injunctions blocking the policy. The D.C. panel called the government’s appeal of the district court’s decision not to lift the injunction unusual, and it may face an uphill battle.

The injunction was issued by the D.C. court before Mattis released his final policy proposal, and the Justice Department argued that it should be lifted because Mattis’ policy is different than Trump’s tweets and earlier memo that sparked it.

“We think that the new policy is clearly different from the old one,” said Brinton Lucas, counsel to the assistant attorney general.

The Mattis policy allows 937 transgender troops who have been diagnosed with gender dysphoria to remain in the military, along with 8,970 others who have identified themselves as transgender in surveys but not sought any treatment, Lucas said.