(AP) – The Wisconsin Supreme Court agreed Thursday to decide whether the state’s 2006 ban on gay marriage was properly put to voters.

The court will review a challenge by political science instructor William McConkey, who claims the referendum on the constitutional amendment illegally put two issues to voters at the same time: whether to ban gay marriage and whether to outlaw civil unions.

A Dane County judge dismissed the case last year, and the Baileys Harbor man appealed that ruling. Last month, the Madison-based District 4 Court of Appeals asked the high court to take the case immediately because of its statewide significance.

Justices announced Thursday they decided to take the case and gave lawyers 30 days to file their initial briefs. The court did not set a date for oral arguments and any decision would not be expected for months.

Fair Wisconsin, the state’s largest gay rights group, praised the court’s decision to take the case.

“The constitutional amendment is definitely something we see as a stain on the constitution. It sort of enshrines discrimination,” said its legislative director, Katie Belanger. “We are really looking forward to the Supreme Court making a fair decision about whether or not the amendment was put to the people in the legal and constitutional way.”

A ruling striking down the amendment would not legalize same-sex marriage because state law still defines marriage as a union between husband and wife. However, it could pave the way for lawmakers to eventually allow it, or for advocates to file lawsuits seeking that right.

Democratic Gov. Jim Doyle has already tried to chip away at the amendment’s impact. Lawmakers are considering his plan to create a statewide domestic partner registry and give same-sex couples 43 benefits enjoyed by married couples, including the right to visit one another in the hospital and inherit each other’s property.

The 2006 referendum asked whether to rewrite the state constitution to define marriage as between one man and one woman and outlaw the state from granting a similar legal status to unmarried individuals. Nearly 60 percent of voters approved making the change, which already had been passed by lawmakers in two legislative sessions as required before going to the referendum.

The justices are expected to decide two issues. The first is whether the two-part question violated a clause in the state constitution that limits referendum questions to a “single subject.”

The second is whether an individual voter such as McConkey, a straight man who has a gay daughter, has the legal standing to sue. Attorney General J.B. Van Hollen argues he does not.

In his ruling last year, Dane County Circuit Judge Richard Niess said McConkey could sue. But he ruled the two clauses in the referendum question were “two sides of the same coin” and properly decided with one vote.

“They clearly relate to the same subject matter and further the same purpose: the preservation and protection of the unique and historical status of traditional marriage,” he said in a ruling from the bench.