A challenge to Utah's same-sex marriage ban by three gay couples is scheduled to be back in court Wednesday as a federal court judge hears arguments in a case being closely watched around the country.

US district judge Robert J Shelby is expected to ask many questions during the hearing, but his ruling will likely come at a later date.

There are 46 similar court challenges to same-sex marriage bans in 22 states, but Utah's case is among the ones being closely watched because of the state's history of being staunchly against the notion of allowing gays and lesbians to wed, said Jon Davidson, director of Lambda Legal which pursues litigation on a wide range of LGBT issues across the country.

Utah is home to the Church of Jesus Christ of Latter-day Saints, also known as the Mormon church, which believes homosexual activity is a sin and is known for its efforts in helping California pass its anti-gay marriage constitutional amendment. And the state was among the first to pass a state amendment banning same-sex marriage, which it did in 2004, Davidson said.

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

Utah state attorneys defend the state amendment by saying it promotes the state's interest in "responsible procreation" and the "optimal mode of child-rearing." Philip Lott of the Utah attorney general's office said he expects emotional arguments during Wednesday's hearing, which starts at 10am and is expected to last about two hours.

Lawyers for the same-sex couples argue the choice of a marriage partner is a "fundamental right and liberty interest" protected by the US constitution and that the state amendment approved in 2004 discriminates against same sex couples in committed relationships.

Peggy Tomsic, the attorney who represents the three couples, said the state can't justify treating same-sex couples differently than opposite-sex couples after last summer's ruling from the US supreme court. In that decision, the country's highest court struck down part of the Defense of Marriage Act, which stipulated that marriage was between a man and woman.

Of the three couples who filed the lawsuit in March, two are lesbians and the other gay men. One of the lesbian couples was legally married in Iowa, Tomsic said. They say the state's ban has caused them humiliation, emotional distress, pain, psychological harm and stigma.

Shelby, the judge overseeing the case, has only been a federal court judge since September 2012. That's when the Senate confirmed his appointment following a nomination by President Barack Obama in November 2011.

He was in private practice in Salt Lake City for 12 years prior to becoming a judge, including working as a commercial litigator and personal injury attorney.

In his short time on the bench, he's gained a reputation of being reasonable, fair, smart and thorough, said Kent Hart, executive director of the Utah Association of Criminal Defense Lawyers.

"He doesn't seem to have any political leanings one way or the other," Hart said. "I think he's just out to follow the law."

Davidson of Lambda Legal has heard Shelby is smart and open-minded, which "Is the most one can hope for," he said.

Shelby has told attorneys that he hopes to make a ruling by early January.