DENVER — In the most prominent challenge of its kind, Hobby Lobby Stores Inc. asked a federal appeals court Thursday for an exemption from part of the federal health care law that requires it to offer employees health coverage that includes access to the morning-after pill.

The Oklahoma City-based arts-and-crafts chain argued that businesses — not just the currently exempted religious groups — should be allowed to seek exception from that section of the health law if it violates their religious beliefs.

The arguments Thursday centered on the Green family, founders of Hobby Lobby Stores Inc. and a sister company, Christian booksellers Mardel Inc. An eight-judge panel peppered both sides with questions about whether the mandate is an undue burden on the Greens’ religious belief.

The Greens contend that emergency contraception is tantamount to abortion because it can prevent a fertilized egg from implanting in the womb. They also object to providing coverage for certain kinds of intrauterine devices.

Hobby Lobby’s lawyer argued that the Greens shouldn’t face fines for not complying with mandatory contraceptive coverage simply because their business makes a profit. The stores are a “profit-making company, yes, but also a ministry,” Kyle Duncan argued.

Duncan cited the Citizens United campaign-finance decision that said corporations have constitutional protections.