Ed Andrieski / AP Rep. Pete Lee, D-Colorado Springs, left, and Rep. Tony Exum, D-Colorado Springs, confer as the civil unions bill is debated in the House Chamber at the Capitol on Monday, March 11, 2013.

Colorado lawmakers on Tuesday approved legislation allowing same-sex couples to enter civil unions, two weeks before the U.S. Supreme Court will hear arguments over whether gays and lesbians can wed.

The state House of Representatives voted 39-26 to pass the “Colorado Civil Union Act,” about one month after the Senate approved the bill. Democratic Gov. John Hickenlooper, who said he will sign the legislation, tweeted: “#CivilUnions passes! Today, every Coloradan has equal rights.”

Some House Republicans said that the bill, which goes into effect May 1, will be challenged because it doesn’t offer religious exemptions. "We won't get to debate this again here, but we will debate this in a court of law," Republican Rep. Lori Saine told The Denver Post.

Five other states allow civil unions, providing state-level spousal rights to same-sex couples, while nine other states, plus the District of Columbia, grant same-sex marriage, according to the National Conference of State Legislatures.

Same-sex marriage is not allowed in Colorado, where voters passed a constitutional amendment in 2006 defining marriage as between a man and a woman. The civil-unions legislation passed on its third try, according to Lambda Legal.

Though lawmakers and others applauded Tuesday’s vote, some said it did not go far enough.

"Of course civil unions and domestic partnerships, no matter how complete the package of protections, are not marriage,” Jennifer Pizer, Lambda Legal's law and policy project director, said in a statement. “True equality is the freedom to marry the one you love and be included under the same laws as your neighbors. It is time to end the exclusion of same-sex couples from marriage, and Lambda Legal and many others will continue to fight for that goal."

The Supreme Court will hear two cases related to same-sex marriage at the end of March: The justices will hear arguments over the constitutionality of Proposition 8, a California law banning same-sex marriage, and the Defense of Marriage Act, federal legislation barring recognition of same-sex marriage.