Three marijuana-related publications have filed a lawsuit in Colorado trying to overturn a provision in the state’s brand-new pot laws.

The publications — High Times magazine, The Daily Doobie and The Hemp Connoisseur — say a new law requiring marijuana-themed publications to be kept behind the counter in stores where they are sold violates free speech rights. The publications say they are being singled out because of their content, which they say is not obscene.

“In enacting this legislation, the State has essentially treated marijuana related magazines as pornography,” the publications argue in a motion for a preliminary injunction against the law that was filed as part of the suit. “However, even pornography distribution enjoys more freedom than this statute permits.”

Gov. John Hickenlooper signed the provision into law just on Tuesday, when he inked multiple marijuana-related bills that create the nation’s first legal recreational marketplace. The laws contain several provisions — including packaging requirements and limits on marijuana advertising — designed to limit the exposure of children to messages about pot. The law on marijuana-themed magazines requires them to be sold behind the counter at places where people under 21 are allowed.

The three publications filed suit Wednesday in federal court in Denver. They are represented by local civil rights attorney David Lane.

Courts are often skeptical of laws that place restrictions on how publications are distributed, the magazines argue in their complaint.

“The Supreme Court has ruled that ‘[t]he distribution of magazines is presumptively protected by the First Amendment,” according to their preliminary-injunction motion.

But supporters of the new limitation on pot magazines say governments can put “time, place and manner” restrictions on speech if they serve a compelling purpose.

“As we legalize marijuana, I think we can also control — in time, place and manner — how it is advertised,” state Rep. Bob Gardner, R-Colorado Springs, told The Associated Press earlier this month. “I think that it’s constitutionally defensible.”

Lawyers for the state and for Hickenlooper — who is named as a defendant in the lawsuit — have not yet responded to the complaint.

John Ingold: 303-954-1068, jingold@denverpost.com or twitter.com/john_ingold