A federal appeals court on Saturday refused to allow the Trump administration to enforce significant parts of an executive order aimed at tightening mail-in voting rules in 23 Democratic-led states, potentially escalating the dispute to the U.S. Supreme Court before the midterm elections.

In a 2-1 decision, the 1st U.S. Circuit Court of Appeals denied the Department of Justice's request to temporarily block a June ruling that had halted several provisions of President Donald Trump's March executive order while the administration pursues an appeal. The Justice Department had previously indicated it could seek emergency relief from the Supreme Court if the appeals court did not rule in its favor.

The administration contended that the lawsuit against the order was premature because federal agencies had not yet finalized the policies required for its implementation. However, the appeals court determined that the plaintiff states were facing imminent election deadlines and had already begun preparations for potential changes.

The majority on the appeals court stated that the district court had reasoned that the executive order outlined clear, rapidly approaching deadlines requiring states to coordinate with federal officials and adhere to new voting procedures. The court added that the plaintiff states had no practical alternative but to respond to the order immediately.

Trump signed Executive Order 14399 in March as part of his broader election integrity agenda. The order directed the Department of Homeland Security to create lists of confirmed U.S. citizens eligible to vote and share them with states. It also instructed the U.S. Postal Service to establish new standards for mail-in ballots and directed the Justice Department to prioritize investigations into state and local election officials who issue federal ballots to individuals deemed ineligible to vote.

The lawsuit was initiated by 23 states and the District of Columbia, with leadership from California, Massachusetts, Nevada, and Washington. These states argued that the Constitution vests them with the primary responsibility for administering federal elections and that the president overstepped his authority by directing federal agencies to impose new voting requirements.

U.S. District Judge Indira Talwani had agreed with the states in June, ruling that several parts of the executive order likely exceeded the president's authority and blocking federal agencies from implementing them in the plaintiff states through the November federal elections. Saturday's decision does not resolve the underlying legal challenge but maintains Talwani's injunction while the appeal process continues.