BOISE, Idaho (AP) — Four couples challenging Idaho's gay marriage ban this week asked a federal judge to block the state from intervening in their lawsuit, arguing such a move would unnecessarily add to their workload and complicate the case.

They filed their lawsuit in U.S. District Court in November against Gov. C.L. "Butch" Otter and Ada County Clerk Chris Rich, contending Idaho's 2006 voter-backed law banning gay marriage violates the U.S. Constitution's equal protection and due process guarantees. Now, the Idaho couples say allowing Idaho to intervene isn't necessary, since Otter is already an adequate representative of its interests.

Attorney General Lawrence Wasden counters Idaho has a strong interest and right to defend its laws. Idaho's case comes as judges in New Mexico, Ohio and Utah ruled in favor of same-sex marriage recently.