Utah brought the battle over same-sex marriage back to the Supreme Court on Tuesday, asking it to block a federal judge’s ruling that the state’s ban on such unions was unconstitutional, a decision that has resulted in a rush to marriage in the conservative state.

The state said U.S. District Judge Robert J. Shelby of Salt Lake City had created a new constitutional right for same-sex couples with his Dec. 20 ruling that the state’s ban violated federal guarantees of equal protection.

Each of the marriages performed since then “is an affront not only to the interests of the state and its citizens in being able to define marriage through ordinary democratic channels,” but also to the Supreme Court’s “unique role as final arbiter of the profoundly important constitutional question,” the state’s request said.

The question — whether state bans on same-sex marriage violate the Constitution’s guarantees of equal protection and due process — is one the Supreme Court sidestepped when it delivered landmark decisions on gay marriage in June.

Utah is not asking the justices to decide that right now. But it wants the marriages stopped while it asks the U.S. Court of Appeals for the 10th Circuit in Denver to review Shelby’s ruling.

Nothing will happen immediately. Utah’s application went to Justice Sonia Sotomayor, the justice designated to receive requests from the circuit. She quickly told attorneys for the three gay couples challenging the state’s ban to respond by Friday to Utah’s filing.

Sotomayor — who happened to be in New York to preside over the Times Square countdown to the new year — could act alone. But usually such requests are referred to the full court.

The Supreme Court delivered carefully weighted decisions on same-sex marriages at the close of its term in June.

In one, U.S. v. Windsor, it voted 5 to 4 to find unconstitutional the Defense of Marriage Act, which withheld federal recognition of same-sex marriages performed where they are legal and denied federal benefits to those in such marriages.

In the other, it allowed to stand a federal judge’s opinion that California’s Proposition 8, banning same-sex marriage, was unconstitutional. The court ruled that the case was not properly presented to it, and avoided a decision on whether state bans offend the U.S. Constitution.

All agreed that question would probably come back to the Supreme Court eventually, but the swiftness of change — and the venue of conservative Utah — has been a surprise. When the court heard arguments in the two cases in the spring, nine states plus the District of Columbia allowed same-sex marriage.

Including Utah, the number now stands at 18. The highest state courts in New Jersey and New Mexico have since ruled the marriages must be allowed.

Same-sex marriage status in the U.S., state-by-state

Shelby, appointed by President Obama but endorsed by Utah’s two conservative Republican senators, became the first federal judge to rule that the court’s reasoning in Windsor meant that a state constitutional amendment banning same-sex marriage could not stand.

“The Supreme Court’s decision in Windsor to strike down DOMA was based on the liberty of individuals to form intimate relationships without being demeaned or degraded by the government,” Shelby wrote.

He said that all of the justifications offered by Utah for passing a law that restricts same-sex couples from the fundamental right to marry were offered by the federal government in defending DOMA, and rejected by the Windsor majority.

And he made note of dissenting justice Antonin Scalia’s words criticizing the majority that it was “inevitable” that the majority’s reasoning would be employed to fight state bans on marriage, even though it traditionally has been an issue decided by the states.

Shelby turned down a late request from Utah to stay his decision — such a request is usually made before the ruling — and the appeals court three times denied the state’s request.

But Utah told the Supreme Court a stay is needed to stop the increasing number of marriages. If the state is successful in overturning Shelby’s decision, it “inevitably will confront the thorny problem of whether and how to unwind the marital status of same-sex unions performed before reversal.”

But the state’s delay in asking the Supreme Court for a stay might hurt its case. Already, about 1,000 same-sex marriages have been performed, out of what the plaintiffs estimate to be about 4,000 same-sex couples in the state.

James Magleby, an attorney for the couples, said there was no reason for the Supreme Court to act.

“The 10th Circuit has already established a rare, expedited briefing schedule on these issues, and hundreds of same-sex couples have already been married in Utah,” Magleby said in a statement. “There is no emergency need for a stay.”

The case is Kitchen v. Herbert.