Six transgender Idaho residents on Thursday sued the state over a new law banning them from using sex-designated public restrooms in public buildings and private businesses, asking a federal judge to strike the law from the books.

Lawyers with the American Civil Liberties Union and its Idaho-based affiliate, along with Lambda Legal, filed the lawsuit in Boise. Lawyers from Munger, Tolles & Olson and Alturas Law Group represented the six residents: Diego Fable, Amelia Milette, Emilie Jackson-Edney, Daniel Doe, Peter Poe and Zoey Wagner.

Gov. Brad Little (R) signed H.B. 752 into law earlier this month after it passed the Republican-controlled state legislature. It states that any person who knowingly and willfully uses the space designated for use by the opposite biological sex will “be guilty of a misdemeanor and may be imprisoned in the county jail for a period to not exceed one year.”

The first offense is a misdemeanor with up to one year in prison, and the second offense becomes a felony with up to five years in prison. The new law, the only one in the nation that applies to private businesses, defines private businesses as any that are open to the public, including shopping malls, hospitals, libraries, rest stops, airports, and gas stations, among others.