U.S. District Judge Indira Talwani of Boston issued a preliminary injunction Friday blocking the U.S. Postal Service from implementing new mail-in voting requirements adopted under President Donald Trump’s March executive order. The ruling extends an earlier temporary order as the legal battle moves through the federal courts.

The USPS rule would require states to provide the agency with lists identifying voters receiving mail ballots and would require outbound and return ballot envelopes to meet new design standards, including unique barcodes. Under the rule, USPS could refuse to deliver ballots that do not meet the requirements or are associated with voters who do not appear on the submitted lists.

The Trump administration argues the requirements are lawful and represent modest changes to USPS procedures. Justice Department attorneys have maintained that state election officials would continue determining who is eligible to vote by mail in their respective states.

Democratic-led states and voting rights organizations challenged the rule, arguing that USPS lacks constitutional authority to regulate state election procedures and warning that the changes could interfere with legitimate ballots. Talwani’s ruling comes as the election calendar is already moving forward, with North Carolina becoming the first state to begin mailing ballots for the November elections Friday.

The administration has asked the Supreme Court to intervene and allow the rule to take effect. The request came after the Supreme Court previously lifted an earlier injunction against the administration’s broader mail-voting directive, while leaving the current legal dispute over the finalized USPS rule unresolved.

Implementation has also raised logistical questions. USPS officials said an online portal intended for states to submit voter lists was not yet operational as of Thursday, although it could become available during the week of September 7. Election officials have also warned that many ballots and envelopes have already been printed under existing state procedures.

The litigation remains ongoing, with the Trump administration pursuing relief in both the federal appeals court and the Supreme Court. The new injunction leaves the USPS requirements blocked while those legal challenges proceed.