(CNN) -- A federal judge in Utah has struck down part of that state's law banning polygamy, after a lawsuit was brought by the stars of the television reality series "Sister Wives."
The ruling late Friday by U.S. District Court Judge Clark Waddoups threw out the law's section prohibiting "cohabitation," saying it violates constitutional guarantees of due process and religious freedom.
But the judge said he would keep in place the ban on bigamy "in the literal sense -- the fraudulent or otherwise impermissible possession of two purportedly valid marriage licenses for the purpose of entering into more than one purportedly legal marriage."
The 91-page decision comes months after the Supreme Court struck down a separate federal law that defined marriage as between only one man and one woman, a major legal, political, and social victory for homosexual couples seeking recognition of their same-sex unions.
The current suit was brought two years ago by Kody Brown, a Utah resident and his four wives -- Meri, Janelle, Christine, and Robyn -- who together have 17 children, and whose lives are chronicled on the TLC cable television program.
They claim their privacy rights were being violated by the decades-old law, passed around the time Utah became a state. They are members of a fundamentalist branch of the Mormon Church known as the Apostolic United Brethren Church.
Brown and his family said in a statement they were grateful for the ruling.
"Many people do not approve of plural families," he said, but "we hope that in time all of our neighbors and fellow citizens will come to respect our own choices as part of this wonderful country of different faiths and beliefs."
Some religious groups criticized the ruling.
"This is what happens when marriage becomes about the emotional and sexual wants of adults, divorced from the needs of children for a mother and a father committed to each other for life," said Russell Moore, of the Southern Baptist Convention. "Polygamy was outlawed in this country because it was demonstrated, again and again, to hurt women and children. Sadly, when marriage is elastic enough to mean anything, in due time it comes to mean nothing."
There was no initial reaction to the ruling from Utah officials, but they are expected to appeal.
The case is Brown v. Buhman (2:11-cv-652).