A federal judge in Washington, D.C., has issued a new order freezing President Donald Trump's attempt to limit mail voting for the midterm elections, adding another obstacle to the administration's effort to rewrite election rules as the Supreme Court is poised to weigh in.

U.S. District Judge Carl J. Nichols late Sunday ordered that the U.S. Postal Service not implement the executive order limiting mail balloting. Nichols wrote in his preliminary injunction that "Plaintiffs have demonstrated that, absent an injunction, there is an increased risk that a significant number of otherwise appropriate absentee or mail-in ballots will ultimately not be counted in the upcoming elections."

This order is similar to one issued earlier by U.S. District Court Judge Indira Talwani in Boston, which is also before the Supreme Court. The nation's highest court is considering the administration's appeal of Talwani's order prohibiting the Postal Service from enforcing its new rule on mail voting before this year's midterm elections.

Nichols had previously refused to issue an injunction in May, ruling the lawsuit was brought too early. The Supreme Court had also cited this reasoning when it lifted an earlier freeze by Talwani. However, the administration issued its rule on Aug. 21, prompting plaintiffs in both Washington, D.C., and Boston to refile their lawsuits.

The new Postal Service regulations originated from an executive order Trump issued earlier this year. Election officials have stated that implementing the changes so close to a general election would be impossible. The regulations would require all ballot envelope designs to be pre-approved by the Postal Service and states to upload the identities of recipients into an online portal.

Mail ballots are already being sent out in at least three states—Alabama, North Carolina, and Wisconsin—and more states are preparing to distribute mail ballots this week. A whistleblower report to Congress warned that millions of people could be disenfranchised if the rule took effect for the midterms. The union representing U.S. Postal Service workers has also pushed back against the executive order, stating that verifying voter eligibility is not the job of postal workers.