DES MOINES (AP) -- The Polk County attorney's office says in new documents that a lawsuit challenging the state's same-sex marriage ban is trying to change the way public policy is made.

The lawsuit has led to a series of filings in which the county attorney's office and a New York-based gay rights organization have answered one another's legal arguments.

Lambda Legal filed the lawsuit in 2005 on behalf of six gay and lesbian couples from Iowa who were denied marriage licenses, as well as three of the couples' children. It names former Polk County recorder and registrar Timothy Brien.

The lawsuit prompted a ruling last August by Polk County District Court Judge Robert Hanson, who said the state law allowing marriage only between a man and a woman violates the constitutional rights of due process and equal protection.

The next day, Hanson stayed the decision, and the case is now before the Iowa Supreme Court.

Challengers of the same-sex marriage ban contend it violates gays' rights. Opponents said the issue should be left up to the Legislature to decide -- not the courts.

In its reply brief filed on Tuesday, the county attorney's office said that Lambda Legal seeks to have the judicial branch set public policy, instead of leaving it to lawmakers.