More than 250 congressional Democrats urged the 5th U.S. Circuit Court of Appeals on Thursday to keep the Food and Drug Administration's telehealth and mail-order rules for mifepristone in place, entering the merits stage of a Louisiana lawsuit that could reimpose a nationwide in-person dispensing requirement.

Mifepristone was approved by the FDA in 2000 and is used in a two-drug regimen for medication abortion.

The amicus brief, filed as the case heads toward oral arguments, was signed by all 47 Senate Democrats and 212 House Democrats.

It backs the FDA's 2023 rule permitting mifepristone to be prescribed by telemedicine and dispensed by mail or at retail pharmacies, a policy Louisiana Attorney General Liz Murrill is seeking to strike down under the Administrative Procedure Act.

The lawmakers wrote that Louisiana "now seeks to re-impose this onerous nationwide restriction on all Americans," warning that granting the state's request would undermine the FDA's congressionally mandated approval process.

The dispute has already run one full lap through the courts.

A three-judge 5th Circuit panel sided with Louisiana on May 1 and reinstated the in-person requirement nationwide while the appeal proceeded, briefly cutting off access to telehealth and pharmacies.

Two weeks later, the Supreme Court blocked that order for the duration of the litigation, over dissents from Justices Clarence Thomas and Samuel Alito, restoring the 2023 rules and sending the case back to the 5th Circuit.

The full appeals court is set to hear oral arguments on Sept. 9.

Louisiana argues that the FDA's 2023 changes were arbitrary under the APA and that mail-order pills undermine the state's near-total abortion ban; the Trump administration's FDA, which has not defended the 2023 rule, is separately conducting a safety review of mifepristone.

Two manufacturers, Danco Laboratories and GenBioPro, intervened to defend the current dispensing rule.

The brief was led by Sens. Patty Murray, D-Wash., Chuck Schumer, D-N.Y., and Ron Wyden, D-Ore., along with House Democratic Leader Hakeem Jeffries, D-N.Y.

Signers argued that Louisiana should not be able to dictate drug policy for the other 49 states and stressed that the in-person requirement was scrapped by the FDA in 2021, before the Supreme Court's Dobbs v. Jackson Women's Health Organization decision, thereby undercutting Louisiana's framing of the rule change as a reaction to state bans.

The 5th Circuit's decision on the merits will govern telehealth and pharmacy access nationwide until the case reaches its next stage of review.