A federal judge late Sunday ordered that the U.S. Postal Service not implement Donald Trump’s executive order limiting mail balloting, adding another obstacle to the administration’s effort to rewrite election rules as the Supreme Court is poised to weigh in on the matter.

The nation’s highest court already is considering the administration’s appeal of an order by U.S. District Court Judge Indira Talwani in Boston prohibiting the Postal Service from enforcing its new rule on mail voting before this year’s midterm elections.

Late Sunday, U.S. District Judge Carl J. Nichols in Washington, D.C., handed down a similar hold on the rule, which was issued Aug. 21.