A new, impartial analysis of a proposed state constitutional amendment to ban gay marriages seems to raise more questions than it answers regarding the potential impact the ballot initiative would have if voters approve it in November.

The analysis of Amendment 3 raises the possibility of a conflict with the U.S. Constitution's Equal Protection Clause because it "creates a classification of persons to whom the right to marry is not available."

It also raises a question about the amendment's second part, which prevents any other union from being given the same or substantially equal legal effect as a marriage.

"The scope of that prohibition may be more precisely defined by Utah courts as they interpret the provision in the context of lawsuits that may arise," the analysis says.

The study will be available Tuesday online at the State Elections Office, www.elections.utah.gov, and in printed form in October.

Gay Taylor, general counsel for the Utah Legislature, was among attorneys who participated in writing the analysis. She said there are "two very credible views" on how the amendment could be interpreted by a judge: simple or vague.

"If there was a case, we could cite to it, but there's not," Taylor said. "It's unclear."

Amendment supporters say the amendment would strengthen existing marriage law and the second part is essential to prevent domestic partnerships, civil unions or other so-called "counterfeit marriages." Opponents say that wording could prevent basic legal protections for unmarried couples, such as hospital visitation or inheritance.

Among supporters who believe the amendment would be interpreted narrowly is Bill Duncan, attorney with the conservative think tank Sutherland Institute.

"If any court were to rule against Amendment 3, it would be a pretty new, pretty radical step," Duncan said. "We have no reason to believe currently that anything like that will happen."

Attorney General Mark Shurtleff and his two challengers have issued a joint statement of concern about the "overly broad language" they say would prohibit the state Legislature from extending "even the most basic partnership rights to unmarried couples."

Dani Eyer, director of the Utah ACLU, said the impartial analysis shows concern about the amendment but is left "very vague."

"It's interesting that the candidates for attorney general and the current attorney general are worried about the impact it would have," Eyer said. The amendment is "so poorly drafted and loose, there's not enough information to make a decision."

Sen. Chris Buttars, R-West Jordan, was the Senate sponsor of the amendment and is co-chairman of the pro-amendment campaign Constitutional Defense of Marriage Alliance. Buttars said he wasn't directly involved in drafting the amendment but is confident of its wording.