(This July 25 story has been repeated with no changes to the text.)

By Nate Raymond

BOSTON, July 25 (Reuters) - A federal appeals court on Saturday declined to allow U.S. President Donald Trump's administration to implement in 23 states his executive order that aims to tighten rules ‌for mail-in voting ahead of November elections that will decide control of Congress.

The Boston-based 1st U.S. Circuit Court of Appeals rejected the administration's request to lift an injunction several Democratic-led states secured on June 25 from a lower-court judge who concluded that key parts of the Republican president's order were unconstitutional.

In asking the court to pause U.S. District Judge Indira Talwani's ruling while it pursues an appeal, the U.S. Department of Justice had argued that because government agencies had yet to finalize actions and policies to implement Trump's directive, any lawsuit challenging his order was premature.

The appeals court, in a 2-1 ruling, rejected that argument.

"As the district court reasoned, the (executive order) lays out a clear set of rapidly approaching deadlines by which states must coordinate with federal officials and comply with new voting procedures - all while the states must also ensure that their officials and the public understand the evolving set of rules that would govern the upcoming September and November elections," the judges wrote. "The Plaintiff States have no practical choice but to respond to the (order) now."

Before Talwani ruled, a federal judge in Washington, D.C., rejected a related effort by Democrats to block Trump's order on similar grounds. The Justice Department warned that absent a ruling in its favor from the 1st Circuit, it may be forced to ask the U.S. Supreme Court to intervene.

TRUMP'S MARCH EXECUTIVE ORDER

Trump signed the executive order in March after years of calling for tighter rules on voting by mail and pushing the false claim that his 2020 election defeat was the result of widespread voter fraud. Under the U.S. Constitution, states are assigned the role of administering federal elections.

That order came on top of other efforts by Trump to overhaul elections. He has made winning approval in Congress of a divisive package of voting restrictions called the SAVE America Act a priority. Judges have blocked an earlier executive order he signed requiring proof of citizenship to register to vote and restricting the counting of mail ballots.

The March order directed the U.S. Department of Homeland Security to compile and transmit to the states a list of confirmed U.S. citizens eligible to vote in each state, derived from citizenship and naturalization records and other federal databases.

Trump's order also required the U.S. Postal Service to only deliver ballots to voters on each state's approved mail-in ballot list. USPS recently moved to implement Trump's directive by issuing new proposed rules requiring states to provide the names and ​barcodes tied to their mail-in ballots.

It also directed the U.S. Department of Justice to prioritize the investigation and prosecution of state and local election officials who issue federal ballots to people deemed "not eligible" to vote.

But Talwani, in siding with a coalition of 23 states and the District of Columbia that was led by California, Massachusetts, Nevada and Washington state, said the president lacked any authority to direct DHS to compile voter eligibility lists for each state to use and that USPS had no statutory authorization to adopt any binding regulations on mail-in voting.

The judge, who was appointed by Democratic President Barack Obama, said Trump also could not attempt through his order "to intimidate local election officials to use the necessarily incomplete confirmed citizenship lists as a resource, lest they face criminal prosecution."