The American Civil Liberties Union has filed a motion asking a judge to to “immediately halt” the Trump administration’s ban on out transgender service members from being enforced while their lawsuit against the ban moves through the courts.

The motion for a preliminary injunction was filed on behalf of the ACLU of Maryland and six current members of the Armed Forces who are transgender. The ACLU says the injunction is necessary to prevent “irreparable harm” that could result if transgender service members are forcibly discharged or rejected when they try to re-enlist, particularly if the ban is found to be unconstitutional.

“Men and women who are transgender should be allowed to serve their country rather than being exposed to this level of uncertainty and harm,” Josh Block, senior staff attorney with the ACLU’s LGBT and HIV Project, said in a statement. “We’re confident the courts will eventually strike down this unconstitutional ban. So we’re demanding a court order to prevent this shameful policy from ever being implemented.”

In its motion, the ACLU argues that the ban violates troops’ constitutional rights, under both the Due Process Clause and the Equal Protection Clause. It also argues that those transgender individuals who serve are entitled to receive the same medical benefits as their cisgender peers.

“Unless this Court issues a preliminary injunction to restore the status quo, Plaintiffs will suffer irreparable harm. On January 1, 2018, Plaintiffs and others who otherwise meet DoD’s strict accession and fitness standards will be denied the opportunity to commission as officers or enlist, simply because they are transgender,” the memo reads.

“No later than March 23 (and in some cases now), Plaintiffs and others with a medical need for surgery will be denied care, simply because they are transgender. On that same day, Plaintiffs and others will lose legal protection and become subject to discharge, simply because they are transgender. And each day that President Trump’s unconstitutional directive remains in effect, Plaintiffs and their families continue to grapple with the stress and uncertainty of having their careers, their livelihoods, and their medical care jeopardized by a Commander-in-Chief who rejects their service and their sacrifice.”

The ACLU says that the ban should be subject to “heightened scrutiny” because transgender people have historically been subject to discrimination and are often singled out for disparate treatment because of characteristics that have nothing to do with their “ability to perform or contribute to society.”

The ACLU also argues that the ban on transgender service constitutes discrimination based on sex, and is motivated by animus toward transgender people and moral disapproval of the way they choose to live their lives by being “out” about their gender identity.

Lastly, lawyers for the six plaintiffs note that the Obama-era policy of allowing transgender soldiers to serve openly was only approved after years of careful study and consideration, which included examining other studies that looked at the effect that allowing transgender troops would have on medical costs, military readiness, and unit morale.

In trying to justify the ban, the Trump administration has used all of these arguments to claim that the presence of transgender people would create disruptions in the various services, ignoring the Obama-era reviews that specifically addressed these concerns.

“President Trump’s abrupt decision to bar men and women who are transgender from serving in the military defies rational explanation,” the ACLU’s memo reads. “All of the justifications advanced in defense of the Ban are either demonstrably false or ‘ma[k]e no sense in light of how the [military] treat[s] other groups similarly situated in relevant respects.’ The anomalous process — in which a surprise Twitter announcement overrode the military’s extensive evidence-based review — confirms that the Transgender Service MemberBan is ‘inexplicable by anything but animus toward the class it affects.'”