Among plaintiffs in the lawsuit was Mondaire Jones, an attorney and the Democratic nominee for the US House of Representatives in New York's 17th Congressional District, representing Rockland and Westchester counties.
Other plaintiffs included New York State Senator Alessandra Biaggi, a Democrat in a district representing the Bronx and Westchester and two Democratic candidates for New York State Assembly: Chris Burdick, who seeks to represent parts of Westchester County and Stephanie Keegan, who seeks parts of Putnam and Westchester counties.
Besides candidates for political office, plaintiffs included individuals who say they must vote by mail because they fear traveling or because they worry about contracting the coronavirus.
Those individuals included a Chicago resident who recently underwent a bone marrow transplant, a digital colourist for film and television who votes in California, an 85-year old Suffolk County, New York, voter at an assisted living facility and Mary Winton Green, a 97-year-old retired philanthropist and Cook County, Illinois voter who first voted in 1944.
"If she cannot vote reliably by mail, she cannot vote at all," the lawsuit said, noting that her doctors have told her she cannot vote in person.
A message seeking comment was left with the Justice Department and the US Postal Service.
As he left the White House Monday, on Trump dismissed claims that he was trying to slow down mail processing.
"Wouldn't do that," he said. "I have encouraged everybody to speed up the mail, not slow the mail. And I also want to have a post office that runs without losing billions and billions of dollars a year."
The lawsuit was filed soon after House Speaker Nancy Pelosi called the House back into session over the crisis at the Postal Service.
Pelosi wants to take up legislation that would prohibit changes at the agency after DeJoy set off a nationwide outcry over delays, new prices and cutbacks just as millions of Americans will begin voting by mail to avoid polling places during the coronavirus outbreak.
The lawsuit cited various news reports and public comments by officials to support its claims that the postal service had imposed a hiring freeze, forbidden overtime and taken stiff measures to prevent steps that usually ameliorate staffing shortages.
- AP
• Correction: This headline on this article has been changed after earlier suggesting the US Postal Service was a party to the lawsuit. The error is regretted.