A Pennsylvania-led coalition of six states and Washington, D.C., on Friday sued the U.S. Postal Service and its top two political appointees, saying they have delayed and disrupted mail delivery in an effort to interfere with mail voting in the November election.

The lawsuit, filed in federal court in Philadelphia three days after Pennsylvania Attorney General Josh Shapiro first announced the plan to sue, says new Postal Service policies were implemented without going through the Postal Regulatory Commission as required by federal law; those policies violate the law setting Postal Service standards; the resulting mail delivery delays disrupt mail voting in a way that interferes with states’ right to determine how votes can be cast; and obstructing the vote-by-mail process violates the Constitution by disproportionately disenfranchising older voters who face health risks from voting in person during the pandemic.

“The service delays caused by Postal Service’s implementation of sweeping new policies in the midst of a pandemic may disenfranchise voters because their ballots will not be sent or received in time and may deter people from voting because they do not trust that their ballot will be delivered,” the suit says.

Pennsylvania was joined in the suit by California, Delaware, Maine, Massachusetts, and North Carolina, as well as the District of Columbia. In addition to the Postal Service, they are suing Postmaster General Louis DeJoy, a top Republican donor whom President Donald Trump appointed in May, and Robert M. Duncan, the chair of the Postal Service Board of Governors, whom Trump appointed in 2017.

Policy changes implemented soon after DeJoy took over the Postal Service have led to mail delays and disruptions across the country, with some neighborhoods in Philadelphia going upward of three weeks without mail. Those changes have raised alarm that voters will be unable to receive and submit mail ballots on time, a key voting method during the coronavirus pandemic.

The Pennsylvania Department of State last week asked the state Supreme Court to extend mail ballot deadlines because of delivery concerns.

Testifying before a U.S. Senate committee on Friday, DeJoy cited the “intimidation of the coronavirus” as a major reason for mail delays in Philadelphia.

He said the availability average of Postal Service employees has dropped about 4% nationwide due to the pandemic. But in urban areas like Philadelphia, which have been hit especially hard, employee attendance is down more than 25%, he said.

“Philadelphia has 750 routes, and we have days where we’re short 200 carriers. And this can go on a while,” DeJoy said. “That’s not the only contribution, but when the American people go two, three days without seeing their carrier, that’s an issue.”

DeJoy also testified he had “no idea” blue mailboxes and sorting machines were being removed until a public backlash over the potential impact on the election. DeJoy abruptly reversed course this week, announcing the Postal Service will suspend planned changes until after the November election. But in addition to blocking further changes, the new lawsuit seeks to reverse policies that have already been implemented.

On Friday, DeJoy assured senators that the Postal Service “is fully capable and committed to delivering the nation’s election mail securely and on time.”