BOISE, Idaho -

A federal judge has denied a request by the Idaho Dairymen's Association to join Idaho in defending the recently passed law criminalizing surreptitious recording at agriculture facilities.

The Times-News reports that U.S. District Judge B. Lynn Winmill shot down the request Monday. Winmill said in his ruling that the state can represent the dairymen's interests without the group getting involved.

Animal rights, civil liberties and environmental groups are suing the state to overturn the so-called "ag-gag" law. The law, which lawmakers passed in February, was backed by Idaho's $2.5 billion annual dairy industry.

Winmill allowed the dairymen's group to file a brief supporting the state.

Those is in favor of the law argue that it protects private property rights. Opponents counter the law infringes on free speech rights.