A federal appeals court in Washington Monday appeared poised to strike down a Federal Communications Commission decision that found the country’s largest cable TV provider discriminated against the Tennis Channel by restricting its distribution to a sports package.

A lawyer for the FCC, Peter Karanjia, faced tough questions from a panel of the U.S. Court of Appeals for the D.C. Circuit, where Comcast Cable Communications is fighting the FCC order. The agency ruling was the first-ever in two decades under a provision of federal communications law that Congress enacted to promote competition and diversity in cable television programming.