The Senate Thursday gave final approval to a measure allowing gay couples to adopt children together and sent it to Governor Ritter.
Current state law allows gay individuals to adopt but not same-sex partners.
Married couples are already allowed to adopt each other's children as stepparents.
The Colorado Catholic Conference and the Colorado Family Institute, a public policy group with links to Focus on the Family, oppose the measure.
They say they'll lobby Ritter to veto it.
Republicans said the measure is aimed at promoting a QUOTE "homosexual agenda" and paving the way toward civil unions for gay couples.
Senator Jennifer Veiga says that's not the issue.
She says gay couples are already raising children together across the state and Colorado should protect those children by giving them two legal parents.