By Nate Raymond

BOSTON, Aug 31 (Reuters) - President Donald Trump's administration on Monday asked a U.S. appeals court to lift a judge's order blocking a new rule that would tighten mail-in voting requirements

ahead of the November congressional elections.

The U.S. Department of Justice asked the Boston-based 1st U.S. Circuit Court of Appeals to put on hold a temporary restraining order that prevented the U.S. Postal Service from enforcing its new rule.

A lower-court judge issued the order on Thursday at the behest of Democratic-led states and voting rights groups.

The administration asked the appeals court to intervene after Boston-based U.S. District Judge Indira Talwani earlier on Monday declined to pause her restraining order. It will remain in place for 14 days while she considers whether to issue a longer-term injunction at a hearing set for Thursday.

Talwani, an appointee of Democratic President Barack Obama, in issuing the restraining order had concluded that USPS' rule risked disenfranchising voters and was likely unlawful and adopted in violation of the U.S. Constitution, which gives states the authority to administer elections.

Justice Department lawyers told the 1st Circuit that Talwani's ruling was "gravely mistaken," and the lawsuit appeared based on an unfounded premise that USPS intends to seize control of the administration of federal elections.

"The rule’s improvements and modernizations of USPS's infrastructure for supporting this particularly sensitive category of mail are fully consistent with USPS's statutory and constitutional authority," the Justice Department argued.

Should the 1st Circuit decline to halt Talwani's order, the administration could try to seek the intervention of the 6-3 conservative-majority Supreme Court, which last week lifted an earlier injunction the judge had issued that had blocked USPS from moving forward with the rule.