Trump’s Justice Department appeared in federal court Tuesday to argue that employers should be able to fire people because they are gay.

In a rare occurrence, all 13 judges of the 2nd Circuit Court of Appeals heard oral arguments in Zarda v. Altitude Express Tuesday. The case originated in 2010 when skydiving instructor Donald Zarda sued his former employer, Altitude Express, alleging he had been fired because of his sexual orientation. The judges are expected to decide if the Title VII provision of the 1964 Civil Rights Act that protects against discrimination based on gender should also apply to discrimination based on sexual orientation.

“Employers under Title VII are permitted to consider employees’ out-of-work sexual conduct,” argued Hashim Mooppan, the Department of Justice attorney. “There is a commonsense, intuitive difference between sex and sexual orientation.”

Tuesday’s oral arguments were an even rarer occasion because another government agency, the Equal Employment Opportunity Commission, was in court to argue against the DOJ, saying gay employees are protected by Title VII. The Justice Department inserted itself into the case in July by filing a brief supporting the employer.

The judges hammered Mooppan, the DOJ lawyer, with questions about why the department decided to weigh in, saying it was “a bit awkward” to have the federal government split on a key legal issue. One judge explicitly asked if the DOJ employment discrimination division had been consulted.

“It’s not appropriate for me to comment,” Mooppan answered.

However the judges decide, the Zarda case could ultimately make it to the high court. A three-judge panel in the 2nd Circuit ruled against Zarda in April but agreed to hear the case again with the full court of 13 judges. And while courts have traditionally stuck to a narrow reading of the Civil Rights Act, this year the 7th Circuit that found the Civil Rights Act protects against sexual orientation discrimination, calling any other interpretation “confusing and contradictory.”

“We need the Supreme Court to decide this issue once and for all,” said Lambda Legal CEO Rachel Tiven. “Today was a rehearsal.”