Does the proposed state constitutional amendment to ban gay marriage go too far? It appears voters will have the chance to hear from both sides of that issue at a debate on Amendment 3.

Scott McCoy, head of Don't Amend Alliance, which opposes the amendment, accepted a challenge to a debate from Susan Roylance, president of Yes! For Marriage, which supports it.

The debate will likely center on the amendment's second part, which would prevent giving the "same or substantially equivalent legal effect" as a marriage to any other relationship.

A heated discussion on that wording followed the official kickoff of a pro-amendment campaign, the Constitutional Defense of Marriage Alliance, Wednesday at the Capitol Complex.

McCoy said the amendment against same-sex marriage, which is already outlawed by Utah state law, would deny unmarried couples basic rights, such as hospital visitation. Roylance said it would protect against same-sex marriage being granted under another name, such as civil union.

"This amendment is not going to harm anyone," Roylance said. "We need to protect marriage in this state from counterfeit marriage."

McCoy countered that he's educating voters about "the true nature of Amendment 3."

"The majority of Utahns believe in the traditional definition of marriage between a man and a woman," McCoy said. "It's not about that, it's about stripping away basic legal rights."

Meanwhile, GOP senators chastised Republican Attorney General Mark Shurtleff behind closed doors Wednesday for coming out against the amendment along with his two opponents, Democrat Greg Skordas and Libertarian Andrew McCullough.

The lawmakers were frustrated to have been blindsided by the attorney general, who called the amendment "a bad law" and said "it could forever deny to a group of citizens the right to approach its Legislature to seek benefits and protections."

Senate President Al Mansell said Shurtleff "admitted it would have been better if he had looked into this a little deeper during the session." But Mansell and other senators said they didn't share the attorney general's concern that the amendment would wind up in court.

"Any time you do action on an issue that is very emotional . . . the side that loses is probably going to litigate," said Sen. Chris Buttars, R-West Jordan. "I think he's right that the gay and lesbian community will bring a legal action no matter what."

Shurtleff sent an e-mail to lawmakers earlier this week promising that if the amendment passes, he "will fulfill my responsibility and defend it in court." He also stated he supports "the appropriate definition of marriage as being between one man and one woman."