NASHVILLE (AP) — A free market think-tank is suing Tennessee officials over a new law that requires online auctioneers to be licensed but exempts some big auction websites like eBay.

Representing two online auctioneer groups and the Interstate Auction Association, the Beacon Center of Tennessee sued members of the Tennessee Auctioneer Commission this week in Nashville federal court. The law takes effect Monday.

The lawsuit contends it's a free speech case, saying auctioneering is entirely speech and people don't forfeit free speech rights because their speech is an occupation. It also contends that the law is in violation of the Commerce Clause.

Lawmakers passed the change without any "no" votes on the House or Senate floor.

Tennessee Auctioneer Commission and attorney general's office officials did not immediately reply to requests for comment.