FILE - In this Friday, Dec. 20, 2013, file photo, Natalie Dicou, left, and Nicole Christensen, right, are married by Salt Lake City Mayor Ralph Becker, middle, in the lobby of the Salt Lake County Clerk's Office in Salt Lake City.

SALT LAKE CITY — Utah will have to recognize same-sex marriages performed in the state starting next Monday unless the U.S. Supreme Court steps in.

The Utah Attorney General's Office was working Monday to petition the high court but did not file anything by the end of the day.

The 10th Circuit Court of Appeals ruled last Friday that Utah failed to prove the need to stay a lower court decision requiring the state to extend marriage benefits to about 1,300 same-sex couples.

A three-judge panel allowed a temporary stay to continue for 10 days so the state could appeal to the Supreme Court. The temporary stay expires at 8 a.m. Monday, July 21.

The state's petition for a stay would be directed to Justice Sonia Sotomayor, who oversees the six states that make up the 10th Circuit. Sotomayor put the brakes on same-sex marriage in Utah last December with an order that appeared to have support of all nine justices because there were no dissenting votes.

But that doesn't necessarily mean the court would intervene in the marriage recognition case, Evans v. Utah.

"It's really hard to handicap it," said Troy Booher, a Salt Lake appellate lawyer.

Part of the reason is the complexities in the relationship with the Kitchen v. Herbert case in which U.S. District Judge Robert J. Shelby struck down Utah's gay marriage ban.

"It's hard to generalize from past experience because hardly ever do you have cases that relate this way and especially one where the Supreme Court has already intervened to grant a stay where the circuit wouldn't in the other case," Booher said.

The high court stepped into the Kitchen case in January only after the 10th Circuit declined to put a hold on Shelby's ruling.

Booher said intuition suggests the Supreme Court would issue a stay in Evans because it did in Kitchen.

"Sotomayor could just say, 'They're related enough. We've already done it once. Why don't we just do it again?' It could be that simple," he said. "But then when you start digging into how dissimilar they are, you think, 'Well, if they step back and think about it, they might not have any inclination to interfere with the 10th Circuit's jurisdiction this time.'"

Bill Duncan, a lawyer and head of the Provo-based Marriage Law Center, said while the Supreme Court stay in the Kitchen case was a 90 percent probability, he sees it as 50-50 in the Evans case.

"This one they could probably avoid in the sense that it's not such a weighty constitutional question," he said. "The ramifications of the decision are pretty confined to Utah."

On the other hand, Duncan said the high court appears to be granting stays in all types of cases where it believes policy should be set at the national level rather than by lower courts.

U.S. District Judge Dale Kimball ruled in May that Utah must extend benefits to same-sex couples who married during the brief time it was legal in the state this past December and January. He temporarily stayed his decision.

The state appealed and asked the 10th Circuit to extend Kimball's stay pending an outcome in the case.

Utah had to prove four things to get a stay from the 10th Circuit: a likelihood of success on appeal, that the state would suffer irreparable harm without a stay, an absence of harm to the opposing party if a stay were granted, and that a stay is in the public interest.

Appellate Judges Carlos F. Lucero and Jerome A. Holmes said the state didn't meet those requirements. Judge Paul J. Kelly disagreed in a dissenting opinion.

Attorneys for the state earlier argued that its appeal would be gutted without a stay. They said allowing the ruling to stand would put Utah at odds with its voter-approved Amendment 3, which prohibits same-sex marriage and recognition of those marriages.

Kelly agreed in his dissent that the appeal might be moot.

"The state and its citizens, and respect for the law, are better served by obtaining complete, final judicial resolution of these issues," he wrote.

The same three 10th Circuit judges in split decision last month found marriage is a fundamental right under the 14th Amendment, and that access to marriage cannot be denied to same-sex couples. The state said it intends to appeal the ruling to the Supreme Court.

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