The Wisconsin Supreme Court is expected to rule Wednesday on the state's gay marriage ban, the AP reported.

The lawsuit challenges the validity of a 2006 constitutional amendment that banned gay marriage and recognition of gay and lesbian couples with civil unions.

William McConkey, a University of Wisconsin-Oshkosh political science professor, filed the lawsuit.

McConkey argues that the ban is not valid because the referendum illegally asked voters to decide on two issues at the same time.

The case was dismissed last year by a Dane County judge, and appealed to the District 4 Court of Appeals. The appeals court asked the Wisconsin Supreme Court to review the case, saying “the validity of the marriage amendment is a matter of significant public interest with statewide implications.”

A win in the state Supreme Court would not legalize gay marriage in Wisconsin because state law defines marriage as a heterosexual union. But it would allow gay and lesbian couples who have been denied a marriage license the right to file a lawsuit.

A large majority of Wisconsin voters (60%) approved the gay marriage amendment in 2006.