DES MOINES &#8212 A Washington interfaith law firm says legalizing same-sex marriages in Iowa would spark a barrage of lawsuits against religious organizations.

The Becket Fund for Religious Liberty filed a brief Friday in a Polk County District Court case in which six gay and lesbian couples have argued that Iowa’s law preserving marriage for only a man and a woman is unconstitutional.

The Becket Fund said it becomes involved in cases “seeking to preserve the freedom of religious institutions to pursue their missions without excessive government regulations and entanglement.”

The group said if Judge Robert Hanson legalizes same-sex marriages, “the Iowa courts would face a wave of church-state litigation created by newly conflicting religious and legal definitions of marriage.”

The group said expanding legal marriage to same-sex couples also will trigger government prohibitions and penalties against religious institutions including:

Ministers and preachers could face hate crime or hate speech conspiracy or incitement lawsuits, if after hearing a preacher’s strongly worded sermon against same-sex marriage, a congregant commits a hate crime against a person or business.

Religious groups could lose government funding, tax exempt status or access to other government programs for opposing same-sex marriages.

Church groups who fire married same-sex employees to make it clear certain behaviors are not condoned may be sued under employment anti-discrimination statutes.

Some religious employers may refuse, on religious grounds, to provide employment health and retirement benefits to a same-sex spouse, prompting discrimination lawsuits.

Religious organizations such as colleges may be sued to force them to extend housing benefits given to traditionally married couples.

Religious institutions offering soup kitchens, hospitals, wedding reception facilities, schools and counseling services may be the subject of discrimination lawsuits if they decline to extend services to same-sex couples.

At a hearing in the Iowa case in May, Des Moines attorney Dennis Johnson argued that the Defense of Marriage Act, which the Legislature passed in 1998, contradicts previous court rulings regarding civil rights and should be struck down.

Johnson said the law is “mean spirited” and was designed only to prohibit gays from marrying. He said it violates the state constitution’s equal protection and due-process clauses.

Lambda Legal, the New York-based gay rights organization that spearheaded a same-sex marriage drive across the country, filed the lawsuit on behalf of the gay and lesbian couples in Polk County District Court on Dec. 13, 2005.