The California Supreme Court issued a unanimous opinion on Thursday that proponents of the state’s same-sex marriage ban have standing to defend the measure against litigation in court.

In the decision, the court determined that anti-gay groups that were responsible for putting Proposition 8 before California voters in 2008 can defend the measure in the case of Perry v. Brown.

“[W]hen the public officials who ordinarily defend a challenged state law or appeal a judgment invalidating the law decline to do so … the official proponents of a voter-approved initiative measure are authorized to assert the state’s interest in the initiative’s validity, enabling the proponents to defend the constitutionality of the initiative and to appeal a judgment invalidating the initiative,” the court wrote.

Each of the seven justices penned their name to the court’s opinion. Associate Justice Joyce Kennard wrote a concurring opinion to “highlight the historical and legal events” that led to the decision.

Groups responsible for Prop 8, including ProtectMarriage.com, are seeking the ability to defend the measure in court because state officials have elected not to participate in litigation against the measure. California Gov. Jerry Brown (D) and Attorney General Kamala Harris (D) have decided not to defend the law — just as former Gov. Arnold Schwarzenegger (R) and Brown in his previous capacity as attorney general chose not to defend it.

The case is pending before a three-judge panel with the U.S. Ninth Circuit Court of Appeals, which in January asked the California Supreme Court to consider whether Prop 8’s proponents had standing to defend the amendment in court.

The California Supreme Court ruling is a recommendation; standing remains a question of federal law. The state court is simply providing advice to the Ninth Circuit on the legal rights of ballot initiative proponents under state law.

After an indeterminate time passes, the Ninth Circuit will make its own decision on whether Prop 8 proponents have standing to defend the measure as it considers the case. Observers say the Ninth Circuit will likely concur that Prop 8 backers can continue the case, then proceed to consider the case on its merits. From there, the case could be appealed to the Supreme Court.

The case arrived at the Ninth Circuit on appeal after now retired U.S. District Judge Vaughn Walker ruled against Prop 8 last year on the basis that the measure violated the Due Process and Equal Protection Clauses of the U.S. Constitution because it singles out gays for unfair treatment under the law.

The lawsuit was filed by the American Federation for Equal Rights, which selected Ted Olson, a U.S. solicitor general under former President George W. Bush, and David Boies, a private attorney and chairman of the law firm Boies, Schiller & Flexner, to lead the case.

In a statement, Olson said he’s “pleased” the California high court has responded to Ninth Circuit’s question and expects swift action from the appellate court.

“Important questions of federal law remain pending before the Ninth Circuit, including, most significantly, the constitutionality of Proposition 8,” Olson said. “We now anticipate a prompt and thorough resolution of those questions by the federal appeals court, which, we expect, will affirm the trial court’s comprehensive and compelling decision that Proposition 8 violates the Due Process and Equal Protection Clauses. We hope that the long wait for justice by gay and lesbian Californians will soon be over.”

Chad Griffin, AFER’s board president, expressed similar confidence and said the lawsuit “is now back on the fast track.”

“We are back in federal court and on the cusp of victory for loving, committed gay and lesbian couples whose constitutional rights are being violated every minute of every day,” Griffin said. “The anti-marriage proponents have no case. We are confident that the higher courts will uphold the District Court’s opinion that Proposition 8 is unconstitutional.”

LGBT advocates have had mixed views on whether granting standing to proponents of Prop 8 would be beneficial for same-sex couples, although most had said they didn’t want the anti-gay groups to be allowed to defend the law in court.

If the Ninth Circuit finds that Prop 8 supporters don’t have standing, the case is dismissed for lack of jurisdiction and California’s marriage ban is lifted. However, some have said granting these groups standing and enabling the case to continue could take it to the U.S. Supreme Court, which could then decide on whether U.S. Constitution provides marriage rights to gay couples throughout the country.

Jon Davidson, legal director for Lambda Legal, called the ruling “disappointing,” but said he anticipates “a quick victory” in the Ninth Circuit for same-sex couples.

“The ruling addresses only a procedural legal question,” Davidson said. “The key question underlying this case is whether the U.S. Constitution permits a state electorate to treat one group of people unequally to everyone else by depriving them of what the state’s high court has held to be a fundamental right. A federal court has already ruled that it may not. We look forward to seeing that decision upheld so that same-sex couples in California may once again enjoy the freedom to marry.”

Shannon Minter, legal director for the National Center for Lesbian Rights, called the ruling a “terrible decision” in terms of its impact on California law.

“The court has given initiative proponents unprecedented and virtually unlimited power, and the people of California will be living with the dangerous consequences of that decision for years to come,” Minter said.

While LGBT groups found the court decision unpalatable, the anti-gay National Organization for Marriage praised the Supreme Court for determining that proponents of Prop 8 should have standing.

Brian Brown, NOM’s president, said “it was shameful” state officials would “abdicate their constitutional responsibility” and elect not to defend the marriage ban in court.

“Although today’s ruling from the California Supreme Court confirms that the proponents of Prop 8 have the right to defend their initiative when the state officials refuse to fulfill their sworn duty, it is gratifying to know that the over 7 million Californians who supported the initiative will have a vigorous defense of their decision in our federal courts,” Brown said.

Brown expressed confidence that the U.S. Supreme Court would overturn against any decision against the marriage ban made by the Ninth Circuit.

“Once this case gets out of San Francisco and reaches the U.S. Supreme Court, we fully expect to be victorious,” Brown said.