A federal judge in Texas on Monday ordered three attorneys for Southwest Airlines to attend "religious-liberty training" from a conservative legal advocacy group as punishment for allegedly violating his ruling in a religious discrimination case brought against the company by a fired flight attendant.

The sanctions order handed down by District Judge Brantley Starr, an appointee of former President Donald Trump, are an unusual demand given that the group, the Alliance Defending Freedom, has a lengthy history of representing religious adherents in high-profile cases seeking to bolster religious protections and roll back LGBTQ and reproductive rights nationwide.

Last year, a jury found that both Southwest and Transport Union Workers discriminated against Charlene Carter when it fired the flight attendant after she "expressed her pro-life beliefs to her union president."

Following the verdict, Starr ordered Southwest to reinstate Carter and take several other corrective actions, including requiring both the airline and the union to "inform Southwest flight attendants that, under Title VII, they may not discriminate against Southwest flight attendants for their religious practices and beliefs, including -- but not limited to -- those expressed on social media and those concerning abortion."

But in messages sent by three Southwest attorneys to the company's employees, according to a sanctions order handed down by Starr, the airline instead said that "Southwest does not discriminate against our Employees for their religious practices and beliefs."

The judge said Southwest also sent around a memo to flight attendants in which the company "lambasts Carter" by taking issue with the conduct she was fired over.

"It's hard to see how Southwest could have violated the notice requirement more. Take these modified historical and movie anecdotes. After God told Adam, '[Y]ou must not eat from the tree [in the middle of the garden],' imagine Adam telling God, 'I do not eat from the tree in the middle of the garden' -- while an apple core rests at his feet. Or where Gandalf bellows, 'You shall not pass,' the Balrog muses, 'I do not pass,' while strolling past Gandalf on the Bridge of Khazad-dûm," Starr wrote.

"The Court concludes that training on religious freedom for three lawyers at Southwest the Court finds responsible (Kerrie Forbes, Kevin Minchey, and Chris Maberry) is the least restrictive means of achieving compliance with the Court's order," the judge said. "The Alliance Defending Freedom ('ADF') has conducted such training in the past, and the Court deems that appropriate here."

The sanctions order was featured earlier Tuesday in the Law Dork newsletter authored by Chris Geidner.

Southwest and Transport Union Workers have appealed the judge's ruling from December, and the airline said in a brief statement to CNN that it plans to appeal Starr's sanctions order.

ADF has a long history of advocating for conservative causes at courts around the country, including the US Supreme Court, where its lawyers successfully represented the plaintiff in a major free speech case this term in which the conservative majority rolled back some key LGBTQ protections.

The group's attorneys are also representing the challengers to a key medication abortion pill in a high-profile case that could also soon land before the high court.

In fillings submitted ahead of Monday's order, attorneys for Southwest urged the judge not to order the trainings, saying that "ordering religious-liberty training would be an inappropriate remedy for the alleged civil contempt."

"Although Southwest contends the Email Notice still substantially complied with the judgment, Southwest has already offered to purge this alleged contempt by providing a corrective notice replacing the 'does not discriminate' language with 'may not discriminate,'" they wrote. "Put another way, there is no conduct for religious-liberty training to remedy."

Starr said in his order that "this isn't the first time an entity has needed religious-liberty training after it attempted to suppress speech," and added that ADF is among other "esteemed non-profit organizations that are dedicated to preserving free speech and religious freedom."

"And some of those entities laudably provide training free of charge for those who have struggled to respect religious liberties in the manner federal law requires," he wrote.

The group said in a statement to CNN that it's "pleased that the judge and jury protected the religious speech of the employee in this case."

"Every company should respect religious liberty and diverse viewpoints in the workplace," said Jim Campbell, the group's chief legal counsel. "We are happy to help Southwest achieve that goal by providing training on Title VII and other applicable laws barring religious discrimination."

Starr's order says the training must last at least eight hours and that it has to be completed by August 28. The airline must also "transport ADF's representative to Dallas and be responsible for any food, accommodation, or other travel expenses for ADF's representative."