Fifteen Democrats on Monday walked out of the Oklahoma House instead of voting on a resolution in support of the Defense of Marriage Act (DOMA), the 1996 law which prevents federal agencies from recognizing the legal marriages of gay and lesbian couples.

The Supreme Court last month heard a case which challenges the constitutionality of DOMA. A ruling is expected in June.

House Democratic Leader Scott Inman and Rep. Kay Floyd, who is openly gay, were among those who walked out.

The resolution, which also reaffirms the state's definition of marriage as between one man and one woman, was approved with an 84-0 vote and now heads to the Senate. Fourteen Democrats voted for the measure.

Republican Rep. Bob Cleveland said the resolution was aimed at sending a message to the Supreme Court.

“Since it's before the Supreme Court and since our President of the United States has came out in favor of redefining the word marriage between one man and one woman, that's what prompted this. We need to make sure that everybody fully understands where we're coming from,” Cleveland told Oklahoma City ABC affiliate KOCO.