SALT LAKE CITY - The Utah Supreme Court on Friday denied an appeal from a convicted polygamist who had argued that the state's laws against bigamy violated his First Amendment right to religious freedom.

Tom Green, 55, lived with five wives and 31 children in a cluster of trailer homes in the remote West Desert, 126 miles southwest of Salt Lake City.

He was convicted in 2002 of child rape of his legal wife, Linda Kunz, who was 13 when she married Green, then 37, in 1986. He had been previously convicted of bigamy and criminal nonsupport for stealing thousands of dollars in child welfare payments from the state.

Defense attorney John Bucher claimed Utah's law against plural marriages violated Green's constitutional rights because polygamy was part of his religion. Bucher also said the state's laws for "cohabitation" were vague, and Green had no way to know he was violating the law by being with other women.

However, in a 23-page decision, the unanimous Supreme Court disagreed, noting that Utah's bigamy statute "does not attempt to target only religiously motivated bigamy. Any individual who violates the statute, whether for religious or secular reasons, is subject to prosecution."

During his trial, Green denied that he lived with any of his wives exclusively or that he intended to be husband and wife with them in any legal sense. At the time, Green argued he was only "spiritually," not legally, married to five women. But a judge determined Green had a common law marriage with Kunz, and jurors found him guilty for cohabiting with the other women.

Assistant Utah Attorney General Laura Dupaix said Green thought he had found a loophole in the bigamy statute.

"He would marry one when she was like 14, because he was worried about criminal charges with a girl that young. Then, when she got older, he would marry another one," but remain in a relationship with the previous women, Dupaix said.

Bucher said he and Green's wives were disappointed in the decision, and his client might request an appeal to the U.S. Supreme Court. He maintained that Utah's statute regulating cohabitation was ambiguous because the word couldn't be legally defined.

"No one knows exactly how long you have to spend with them or how much sexual intercourse is involved," he said.

Though polygamy has been illegal for more than 100 years in Utah, it's believed that thousands of people continue the practice - which was advocated by founding Mormon pioneers and remains in Church of Jesus Christ of Latter-day Saints scripture. Utah officially outlawed polygamy in 1890 as a condition of statehood.

Green is perhaps Utah's most prominent polygamist. He emerged from obscurity and onto the sets of television talk shows, arguing his lifestyle was a constitutional right.

Prosecutors say they first learned about Green's case from those shows.

The Utah Board of Pardons and Parole has set Green's prison release date for August 2007.