AT&T Inc., with backing from the U.S. Chamber of Commerce, is asking the U.S. Supreme Court to overturn a 7th U.S. Circuit Court of Appeals ruling that the company says would let a lot more labor disputes boil over into arbitration.

The case grew out of an International Brotherhood of Electrical Workers lawsuit against AT&T’s Midwest subsidiary, Illinois Bell Telephone Co., in which the union sought to compel arbitration concerning new “work performance guidelines” the company imposed on sales staff.