(CNN) - The program that operates small post offices inside dozens of Staples stores is being met with a big backlash.
That's because these so-called mini post offices aren't staffed with postal service employees, but rather Staples workers.
The unions are concerned that could lead to job losses and along with them, good wages and benefits for members.
A postal service spokeswoman rejects that idea, saying the pilot program at Staples is the next step of a program that already has over 65,000 retail partners like grocery stores and pharmacies that sell stamps.
Many rural stores also sell flat-rate shipping boxes.
The American Postal Workers Union does say it would be willing to support the program, as long as it's staffed with USPS employees, but that's not the plan for now.
The postal service counters are currently available at just over 80 stores in San Francisco, San Diego, Atlanta, Pittsburgh and Worcester, MA.
It's not shocking that the unions are upset.
The post office has been struggling financially for years, recently defaulting on a $5.6 billion payment for retiree healthcare benefits.
Unlike other federal agencies, the postal service is not funded by taxpayers and is meant to function like a private business.
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