They say at least 30 letter-sorting machines have been removed from Pennsylvania mail facilities.
The partisan fight over postal service is casting a shadow over the coming presidential election, with millions in Pennsylvania expected to vote by mail amid the coronavirus pandemic.
In testimony during a six-hour House Oversight Committee hearing last week, DeJoy vehemently refused to restore decommissioned mail-sorting machines and blue collection boxes, saying they are not needed.
DeJoy also said he would continue policies limiting when mail can go out, as well as halting late delivery trips, which postal worker union officials in Pennsylvania said Tuesday are continuing to contribute to the slowdown in delivery around the state.