SALT LAKE CITY — Utah intends to appeal a federal judge's ruling that struck down part of the state's anti-polygamy law in a lawsuit filed by the family that appears on the TV show "Sister Wives."

Attorney General Sean Reyes filed a notice of appeal in U.S. District Court late Wednesday. The state now has 14 days to submit its arguments to the 10th Circuit Court of Appeals in Denver.

Kody Brown and his four wives challenged Utah's bigamy law in 2011, saying it violated their constitutional rights. Utah County Attorney Jeff Buhman threatened to prosecute them after "Sister Wives" debuted but ultimately did not file charges. The family eventually moved from Lehi to Las Vegas.

Judge Clark Waddoups ruled that a provision of the law forbidding cohabitation violated the Browns' freedom of religion.

The state sought to have the suit thrown out after Buhman adopted a policy not to prosecute bigamy unless it occurs with another crime or if a person in the relationship is under 18.

The Browns' attorney, Jonathan Turley, said the Browns are prepared to defend Waddoups' ruling that reaffirmed freedom of religion and equal protection.

"It is a rather curious position for the state of Utah in seeking to reverse one of the strongest defenses of religious liberty handed down in decades," he posted on his blog.

— Dennis Romboy