A federal judge in Michigan who had been expected to rule on the state's ban on same-sex marriage decided instead to hold a trial on the issue.
U.S. District Judge Bernard Friedman said Wednesday he would not make a decision without hearing testimony. He set a trial for Feb. 25.
"I'm in the middle. I have to decide this as a matter of law. I intend to do so," Friedman told the parties at a hearing in Detroit, according to a live blog of the court proceedings published by the Detroit Free Press.
The proceedings are the latest since the U.S. Supreme Court in June ruled out portions of the federal Defense of Marriage Act. That ruling has touched off court action in other states, including New Jersey, Pennsylvania, North Carolina and Utah.
In the Michigan case, two Detroit-area nurses in a relationship - April DeBoer and Jayne Rowse - are raising three adopted children with special needs. They filed a lawsuit in 2012 hoping to strike down a state law that bars same-sex partners from adopting one another's children.
The case was important in what it sought, but Friedman suggested challenging the gay marriage ban as well because, if it were overturned, other laws, such as the adoption restriction, would probably fall.
A constitutional amendment declaring marriage as between a man and a woman was approved by 59% of Michigan voters in 2004.
Attorneys for DeBoer and Rowse argued that the amendment violated the Equal Protection Clause of the U.S. Constitution.
The state has argued that it has the right to regulate the terms of marriage.
"Defining marriage as between one man and one woman furthers Michigan's legitimate interests in attempting to provide the optimal family setting for its children," the attorney general's office said in a court filing.