Utah's case is contentious because the Church of Latter Day Saints, based in the state, strongly denounces gay marriage. Mario Tama/Getty

A federal judge in Utah, one of America's most conservative states, heard arguments Wednesday in a case brought against the state's same-sex marriage ban.

An attorney for three gay couples argued that the court should strike down Utah's same-sex marriage ban because a precedent was set by the U.S. Supreme Court when in June it declared unconstitutional part of the Defense of Marriage Act, which had declared marriage between a man and a woman.

Utah voters approved an amendment to the state's constitution in 2004 that defined marriage as solely between a man and woman. The couples first filed the lawsuit in March, the Salt Lake City Tribune reported.

Though more than 40 similar court challenges to same-sex marriage bans are pending in 22 states, Utah's is among the most closely watched because of the state's history of staunch opposition to gay marriage, said Jon Davidson, director of Lambda Legal, which pursues litigation on a wide range of Lesbian Gay Bisexual and Transgender (LGBT) issues across the country.

Utah is home to The Church of Jesus Christ of Latter-day Saints, or the Mormon Church, which believes homosexuality is a sin. The state was among the first to pass an amendment banning same-sex marriage, Davidson said.

"Utah has a particularly symbolic position in the history of the struggle of same sex couples to be able to marry," Davidson told The Associated Press.

According to the Tribune, the couples' names are: Derek Kitchen and Moudi Sbeity; Laurie Wood and Kody Partridge; Karen Archer and Kate Call.

During a nearly four-hour hearing in U.S. District Court in Salt Lake City — in front of an audience of about 100 people — Peggy Tomsic, one of the lawyers for the plaintiffs, contended that marriage is a fundamental right protected by the U.S. Constitution.

"This case embodies the civil rights movement of our time," Tomsic said. "This is the time and this is the place for this court to make it clear that the 14th Amendment is alive and well, even in Utah."

The Mormon Church, a prominent figure in the same-sex marriage debate in Utah, helped fund the battle to ban same-sex marriage in California. The measure passed there in 2008, prompting a long legal battle that culminated in the U.S. Supreme Court declaring it unconstitutional in 2012. In the Utah case, U.S. District Judge Robert J. Shelby heard arguments from both sides as he weighed what will be a precedent-setting decision that he is expected to make by early next year.

His ruling would be the first on a state same-sex marriage ban since the Supreme Court's DOMA ruling.

Attorneys for the state of Utah asserted it is not the court's job to determine how a state defines marriage, and that the Supreme Court ruling doesn't give same-sex couples the universal right to marry.