The state will defend a civil unions law on behalf of the state Department of Health, but Gov. Neil Abercrombie has filed a separate response acknowledging that the law is unconstitutional because it does not allow same-sex couples to marry.

“Under current law, a heterosexual couple can choose to enter into a marriage or a civil union,” Abercrombie said in a statement. “A same-sex couple, however, may only elect a civil union. My obligation as governor is to support equality under law. This is inequality, and I will not defend it.”

A lesbian couple has sued the state in federal court alleging that the civil unions law violates their due process and equal protection rights under the U.S. Constitution. The lawsuit names Loretta Fuddy, the director of the state Department of Health, and Abercrombie as defendants.

The state will defend the civil unions law on behalf of Fuddy. “The Department of Health is charged with implementing the law as passed by the Legislature. Absent any ruling to the contrary by competent judicial authority regarding constitutionality, the law will be enforced,” Fuddy said in a statement. “Because I am being sued for administering the law, I will also defend it.”