U.S. Sen. Bernie Sanders, I-Vermont, joined 20 Senate colleagues on Wednesday to urge Postmaster General Louis DeJoy to stop any changes to U.S. Postal Service standards that would result in job losses and further degrade mail delivery performance, especially in rural states.

Sanders, along with Sen. Angus King, I-Maine, and 19 Democrats said mail processing facility reviews are underway at 59 locations across 35 states.

Included in the reviews is the mail processing facility in Kingsford, where potential changes could move some of its operations to Green Bay, Wis.

While the USPS claims “there will be no career layoffs or slowed service, we are concerned these facility reviews will functionally result in both,” the letter states. The senators are concerned about the long distances mail will have to travel and the potential for delayed service in multiple states.

“In many instances, outgoing mail processing will move hundreds of miles to a regional facility, outside reasonable commuting distance and, in some cases, to another state entirely,” they said.

For communities near facilities under review, it’s unclear how local first-class mail will meet its two-day standard while traveling hundreds of miles for sorting, they added.

“Americans all over the country — particularly in rural states — depend on reliable and expedient mail service to conduct business, pay their bills, receive medication including lifesaving prescription drugs, get their Social Security checks, and stay in touch with loved ones,” the senators wrote. “For rural communities, the loss of local jobs and even slower mail service represent further setbacks to the revitalization of rural life.”

Wednesday’s letter led by Sanders follows a similar letter to DeJoy shared last month by U.S. Sen. Gary Peters, D-Mich.

“On Dec. 5, 2023, I requested information about these national plans, including the scope of the plans and how USPS has studied their impacts,” Peters wrote. “In line with USPS’s mission of reliably serving every community, it must ensure transparency and substantiate that any changes will not adversely impact service. USPS must respond in full to that request,” he said.

Peters has also asked for details about the Kingsford facility review, seeking assurances that any changes won’t harm Upper Peninsula mail service.

U.S. Rep. Jack Bergman, R-Watersmeet, has written to DeJoy as well, urging the postal service “to avoid any actions and oppose any changes that would negatively impact local mail operations and services” in the U.P.

The letter from Sanders and colleagues was also sent to the USPS Board of Governors, which has two vacancies. The Board of Governors selects the postmaster-general and appointed DeJoy in 2020 under former Republican President Donald Trump.

In all, the board has nine presidentially appointed, Senate-confirmed slots, according to Government Executive.

Last month, President Joe Biden nominated former Labor Secretary Marty Walsh to fill one of the vacancies. Walsh would be the fourth Democrat to sit on the board, joining three Republicans and one Independent.