A federal appeals court has upheld an injunction halting the Trump administration’s efforts to enforce a controversial executive order restricting mail-in voting across nearly half of the United States ahead of November’s elections.

In a 2-1 decision issued Saturday, a panel for the First U.S. Circuit Court of Appeals rejected a request by the Department of Justice to lift a preliminary injunction granted last month. The ruling maintains a block on President Donald Trump’s March executive order, which directed federal agencies—including the Department of Homeland Security, the Social Security Administration, and the U.S. Postal Service—to create a “state citizenship list” of eligible voters and restrict mail ballot delivery strictly to individuals appearing on that index.

The legal challenge was mounted by a coalition of Democratic state officials representing twenty-three states and the District of Columbia, led by states including California, Massachusetts, Nevada, and Washington. The coalition argued that the president’s order violates the U.S. Constitution, which explicitly assigns authority over the administration of federal elections to state legislatures and Congress, rather than the executive branch.

U.S. District Court Judge Indira Talwani ruled in favor of the states in June, concluding that the administration lacked statutory authority to overhaul mail-in voting rules or intimidate state election officials under threat of federal prosecution. On appeal, the Justice Department argued the lawsuit was premature because final rules implementing the order had not yet been formally enacted. However, the appellate panel rejected that argument, stating that state election administrators faced immediate financial and operational burdens to comply with rapidly approaching election deadlines.

Following Saturday’s decision, the Justice Department announced it is reviewing its legal options, signaling that it may ask the U.S. Supreme Court to intervene before the fall elections.