Tennessee, like Georgia, has a state constitutional amendment banning same-sex marriage and also denying recognition of same-sex legal unions from other states.
In August, gay couples in Nashville and Memphis attempted to get marriage licenses knowing they would be turned down but also knowing they would sue the state.
The Tennessee Equality Project, an LGBT advocacy organization, announced lawyers and couples would announce the lawsuit today at the Davidson County Courthouse in Nashville.
This morning, Gov. Chris Christie of New Jersey dropped his appeal to stop same-sex marriages.
UPDATE: Four same-sex couples legally married in New York and California sued the state of Tennessee for not recognizing their marriages.
From a press release from the National Center for Lesbian Rights:
Today, four legally married same-sex couples who live in Tennessee filed a lawsuit in federal district court in Nashville, challenging Tennessee laws that prevent the state from recognizing their marriages and treating them the same as all other legally married couples in Tennessee. The couples, who include a full-time Army reservist and his husband and two professors of veterinary medicine, all formerly lived and married in other states and later moved to Tennessee to pursue careers and make new homes for their families. Tennessee law currently prohibits recognition of their marriages and treats the couples as legal strangers.