For transgender service members, the April 12 deadline just became even more urgent.

On Tuesday, the D.C. Circuit Court of Appeals officially dissolved the sole remaining preliminary injunction against the Trump administration’s transgender troop ban.

The ban can now go into effect next month, barring any further legal developments.

In a brief order on Tuesday, the D.C. Circuit Court of Appeals, which had previously issued an opinion in January vacating the D.C. District Court’s injunction, issued a mandate formally putting that opinion into effect.

The absence of that mandate was the last legal obstacle standing in the way of the Trump administration’s new policy, which will impose restrictions on military service for those who are diagnosed with gender dysphoria, beginning on April 12. Three other preliminary injunctions against the transgender troop ban had already been stayed.

But even if the transgender troop ban goes into effect, LGBT advocates won’t give up.

“Today’s ruling only drives home the urgency of continuing to fight this destructive policy, which we will continue to do,” Shannon Minter, legal director for the National Center for Lesbian Rights, told The Daily Beast in a statement.

NCLR and GLBTQ Legal Advocates & Defenders, or GLAD, represent transgender service members in the D.C. challenge against the transgender troop ban. For NCLR and GLAD, Tuesday’s ruling marks a setback, if not an entirely unexpected one.

In January, the Supreme Court lifted two of the injunctions that were preventing the transgender troop ban from going into effect—though it did not rule on the merits of the case. After that 5-4 decision, two injunctions remained: one in Maryland, one in D.C.

On March 7, the District Court of Maryland granted the Trump administration’s request to stay its injunction. That left just one injunction in D.C. District Court.

Even though the D.C. Circuit Court of Appeals did not issue its mandate dissolving the D.C. District Court’s injunction until this Tuesday, the Trump administration earlier this month attempted to move forward regardless with plans to implement the troop ban.

In a legal filing on March 8, the Justice Department acknowledged that the D.C. Circuit Court of Appeals “has not issued the mandate” but claimed that its judgment “took effect when entered.”

(“That is just not the law,” Minter told The Daily Beast last week, characterizing the Trump administration’s legal strategy as “aggressive.”

“The law is that an opinion does not take effect until the mandate issues,” he added.)

U.S. District Judge Colleen Kollar-Kotelly also rebuffed the Trump administration last week, writing in a D.C. District Court that “the nationwide preliminary injunction issued by this Court remains in place,” as BuzzFeed News reported.

“Absent a mandate, the D.C. Circuit’s [decision] vacating this Court’s preliminary injunction is not final,” Judge Kollar-Kotelly continued.

While waiting for that mandate, LGBT advocates and the Trump administration both issued legal filings earlier this week supporting and opposing the remaining injunction, respectively. But the Tuesday order from the D.C. Court of Appeals makes those filings irrelevant. There were once four injunctions against the ban; now there are zero.

As Minter explained, there are still legal options left on the table for LGBT advocates—such as seeking a rehearing of the case—but for the moment, “there is no legal barrier to the government’s intended plan to start enforcing the Mattis ban on April 12.”

For many transgender service members, this is the worst-case scenario: On April 12, service members who have already transitioned or begun transitioning will be allowed to stay in the armed forces for the time being because they will be grandfathered in under the revised policy introduced by former Defense Secretary James Mattis in 2018.

But those who have not yet received a gender dysphoria diagnosis now have 17 days to get one if they want to retain their jobs. As The Daily Beast previously reported, several transgender service members are currently racing the clock—and overcoming logistical hurdles—to get a diagnosis in time.

More legal wrangling over the D.C. injunction could have potentially bought some time for those transgender service members in need of a diagnosis; now, the April 12 deadline remains firm—and as Minter noted, many of those service members are still “scrambling to come out and initiate a gender transition.”

After that deadline, transgender service members who are not willing to suppress their identity and live as their birth-assigned sex will face discharge.

“ The government’s plan is already wreaking havoc in the lives of dedicated transgender troops who must now face the grim choice of suppressing their identity or leaving military service, to the detriment of their fellow service members and national security. ”

Transgender civilians wishing to enlist will effectively be barred from doing so under strict new accessions standards that will disqualify those who have received transition-related medical care like hormone therapy and sexual reassignment surgery.

Those new measures don’t go into effect until April 12—but their effects are being felt now.

“The government’s plan is already wreaking havoc in the lives of dedicated transgender troops who must now face the grim choice of suppressing their identity or leaving military service, to the detriment of their fellow service members and national security,” said Minter.

In a statement, a Department of Defense spokesperson told The Daily Beast: “We are pleased the court cleared the way for the Department of Defense to be able to implement personnel policies it determined necessary to best defend our nation.”