The lawsuit by the Oklahoma City-based chain claims the government mandate is forcing the company’s owners “to violate their deeply held religious beliefs under threat of heavy fines, penalties and lawsuits.” Failure to provide the drugs in the company’s health insurance plan could lead to fines of up to $1.3 million a day, the company said.

“By being required to make a choice between sacrificing our faith or paying millions of dollars in fines, we essentially must choose which poison pill to swallow,” David Green, Hobby Lobby CEO and founder, said in a statement. “We simply cannot abandon our religious beliefs to comply with this mandate.”

The lawsuit, filed in U.S. District Court in Oklahoma City, alleges the Health and Human Services mandate is unconstitutional and requests an injunction to prohibit it from being enforced. Hobby Lobby is self-insured and will be required to comply with the mandate by Jan. 1, the start of its health insurance plan year.

“We are confident that the court will act quickly,” said Kyle Duncan, general counsel for the Becket Fund for Religious Liberty in Washington, which represents Hobby Lobby. Duncan said 27 other lawsuits have been filed nationwide over the mandate, mostly by nonprofit groups.

“This mandate violates the religious liberty of millions of Americans,” Duncan said. “The government has turned a deaf ear to the rights of business owners.”

Duncan said the lawsuit does not challenge rules regarding a variety of other birth-control measures.

Charles Miller, spokesman for the civil division of the Department of Justice, said the agency had no comment on the lawsuit.