Pennsylvania attorney general Kathleen Kane announced Thursday afternoon she will not defend the state in a federal lawsuit filed this week challenging the constitutionality of the state’s ban on same-sex marriage, calling the prohibition "wholly unconstitutional."

The American Civil Liberties Union filed suit Tuesday on behalf of 23 Pennsylvania residents, including 10 couples, a widow and two children, naming Kane and the state's Republican Gov. Tom Corbett as defendants. Kane's move, announced to reporters at Philadelphia's National Constitution Center, places the burden of defending the law on the governor's general counsel. Corbett supports the prohibition on same-sex marriage, which passed the state legislature in 1996.