Oregon Attorney General Ellen Rosenblum said in a federal court filing Tuesday that the state's ban on gay marriage “serves no rational purpose.”

Rosenblum said that the state was prepared to begin issuing marriage licenses to gay and lesbian couples if District Judge Michael McShane were to strike down the state's 2004 voter-approved constitutional amendment limiting marriage to heterosexual couples.

“The state defendants in this case recognize that the ban on same-sex marriage serves no rational purpose and harms Oregon citizens,” Rosenblum wrote in her 35-page filing. “This case presents that rare case in which there simply is no legal argument to be made in support of a state law.”

“If this Court determines that Oregon's prohibition on same-sex marriage violates plaintiffs' rights under the federal constitutional, the state is prepared to implement that ruling,” the brief concludes.

Mike Marshall, campaign manager for Oregon United for Marriage, the coalition working to legalize marriage for gay couples, applauded the move.

“We are literally counting down the days until all loving and committed couples in Oregon have the freedom to marry, and we are thrilled that the attorney general is on the right side of history,” Marshall said in an emailed statement.