Lawyers for transgender teen Gavin Grimm and his Virginia school district told the U.S. Supreme Court on Wednesday that it should go ahead and decide whether existing federal law protects against gender identity discrimination in public schools.

The two sides agreed that the justices can and should decide whether the text of Title IX of the Education Amendments of 1972, which prohibits sex discrimination in schools that receive federal funding, controls Grimm’s case. The teen sued his high school after it adopted a policy barring him from the restroom that the other boys in his school use.

What the sides don’t agree on is just when the court should resolve the case. And the timing could make all the difference if a ninth justice joins the court.

In a nod to the administration of President Donald Trump, which last week withdrew federal guidance on how public schools should accommodate transgender students seeking bathroom equality, the Gloucester County School Board urged the justices to first formally seek the views of the federal government ― an intervention that could postpone the March 28 hearing.

“It would be unusual for the Court to address questions of the sort presented here without first hearing from the Solicitor General,” Kyle Duncan, who represents the school board, said in a letter to the Supreme Court.

The Trump administration isn’t a part of the suit, but the U.S. Solicitor General’s Office, which represents the government before the Supreme Court, often participates in cases in which it’s not a party and yet major questions of federal law are at stake.

Delaying resolution of that question will only lead to further harm, confusion, and protracted litigation for transgender students and school districts across the country. Joshua Block, ACLU lawyer representing Gavin Grimm

Last week, the office advised the court in a courtesy letter that the departments of Justice and Education had rescinded Obama-era guidelines issued last May that are at issue in Grimm’s case, but it didn’t take a position on the legality of the guidelines.

Those guidelines had interpreted Title IX to cover gender identity discrimination, and Grimm scored a major victory in federal court thanks to that interpretation. But that was followed by a wave of challenges to the guidelines in other parts of the country, and a federal judge in Texas blocked the Obama administration from enforcing them nationwide.

Joshua Block, the American Civil Liberties Union lawyer representing Grimm, said in his letter to the Supreme Court that this legal uncertainty will “inevitably” require the court to settle how Title IX should be read.

“Delaying resolution of that question will only lead to further harm, confusion, and protracted litigation for transgender students and school districts across the country,” Block wrote. “Another few years of needless litigation would not help clarify the legal question facing the Court, and it would impose enormous costs on individual students until the Court provides additional clarity.”

If that’s how things proceed and the hearing in Grimm’s case gets postponed a month, the Supreme Court could very well be fully staffed for what is now the biggest case of its current term.

“As a transgender student and thinking about transgender students everywhere, hearing that your presidential administration has gone out of its way just to further discriminate against you ... it’s very upsetting and disappointing news,” Grimm told The Huffington Post on the day the administration withdrew the guidelines.