OKLAHOMA CITY – An Oklahoma state agency is suing the federal government in an attempt to block a local military base from ending its contract with a vendor who employs blind workers.

The Oklahoma Department of Rehabilitation Services filed the lawsuit in federal court on Tuesday. That agency is tasked with expanding independence and economic self-sufficiency for disabled Oklahomans. The lawsuit is against the United States of America, by and through Secretary of Defense James Mattis and Secretary of the Army Mark Esper.

The complaint requests a restraining order and injunctive relief to block Fort Sill, the Army post in Lawton, from ending its contract with a cafeteria services vendor.

The argument hinges on the Randolph-Sheppard Vending Facility Act. The law was passed in the 1930s and gives priority to blind vendors, who are licensed as so through the state, when choosing vendors operating on federal property, such as military installations.

The current vendor, David Altstatt, is the Department of Rehabilitation Services-appointed blind vendor for the Army post. The current contract includes one base year and four option years, and Altstatt’s company is in the second option year, according to the lawsuit. In February, the defendants notified rehabilitation services officials that they intended to terminate the contract. The department argues that the defendants didn’t give proper notification to the U.S. secretary of education, who oversees the program. The Oklahoma rehabilitation department requested arbitration with that secretary and defendants in April, according to the lawsuit. In August, the defendants issued a solicitation for a replacement vendor. That solicitation is what the lawsuit attempts to block.