SEATTLE — A U.S. judge on Thursday blocked controversial Postal Service changes that have slowed mail nationwide, calling them “a politically motivated attack on the efficiency of the Postal Service” before the November election.

Judge Stanley Bastian in Yakima, Wash., said he was issuing a nationwide preliminary injunction sought by 14 states that sued the Trump administration and the U.S. Postal Service.

The states challenged the Postal Service’s so-called “leave behind” policy, where trucks have been leaving postal facilities on time regardless of whether there is more mail to load. They also sought to force the Postal Service to treat election mail as First Class mail.

The judge noted after a hearing that Trump had repeatedly attacked voting by mail by making unfounded claims that it is rife with fraud. Many more voters are expected to vote by mail this November because of the COVID-19 pandemic, and the states have expressed concern that delays might result in voters not receiving ballots or registration forms in time.

Bastian, an appointee of former President Barack Obama, said the changes created “a substantial possibility many voters will be disenfranchised.”