Iowa’s House has approved a measure that seeks to ban gay marriage in the state.
The state legalised marriage for couples in 2009 after Supreme Court judges said a ban violated the constitution.
However, opponents still pushing to repeal the law.
The lower chamber has approved a constitutional amendment – the Iowa Marriage Amendment – to restrict marriage to heterosexual couples by 62 votes to 37.
At least two Democrats voted for the measure.
Mike Gronstal, the Democratic majority leader of the Iowa Senate, reportedly plans to block the measure from being debated in the upper chamber.
He said the vote was “a big step backwards for the constitutional rights of all Iowans”.
Earlier this week, hundreds of people attended a public debate on the measure at the Iowa House.
While some spoke out against gay marriage, student Zach Wahls, 19, told the room about his upbringing with lesbian mothers.
“Our family really isn’t so different from any other Iowa family,” he said.
“You know, when I’m home we go to church together; we eat dinner; we go on vacations. … We’re Iowans. We don’t expect anyone to solve our problems for us. We’ll fight our own battles. We just hope for equal and fair treatment from our government.”
In November, Iowa voters ousted three of the seven Supreme Court judges who ruled that the state’s ban on gay marriage was unconstitutional.
Supreme Court Chief Justice Marsha Ternus and associate justices Michael J Streit and David L Baker were voted out of office in what gay marriage opponents claimed as a victory.
Anti-gay marriage groups including the National Organization for Marriage, the Family Research Council, and the American Family Association conducted a $1 million campaign to remove the three judges.