(San Francisco, California) California’s highest court agreed Wednesday to hear several legal challenges to the state’s new ban on same-sex marriage but refused to allow gay couples to resume marrying before it rules.

The California Supreme Court accepted three lawsuits seeking to nullify Proposition 8, a voter-approved constitutional amendment that overruled the court’s decision in May that legalized gay marriage.

All three cases claim the measure abridges the civil rights of a vulnerable minority group. They argue that voters alone did not have the authority to enact such a significant constitutional change.

As is its custom when it takes up cases, the court elaborated little. However, the justices did say they want to address what effect, if any, a ruling upholding the amendment would have on the estimated 18,000 same-sex marriages that were sanctioned in California before Election Day.

Gay rights groups and local governments petitioning to overturn the ban were joined by the measure’s sponsors and Attorney General Jerry Brown in urging the Supreme Court to consider whether Proposition 8 passes legal muster.

The initiative’s opponents had also asked the court to grant a stay of the measure, which would have allowed gay marriages to begin again while the justices considered the cases. The court denied that request.

The justices directed Brown and lawyers for the Yes on 8 campaign to submit arguments by Dec. 19 on why the ballot initiative should not be nullified. It said lawyers for the plaintiffs, who include same-sex couples who did not wed before the election, must respond before Jan. 5.

Oral arguments could be scheduled as early as March, according to court spokeswoman Lynn Holton.

“This is welcome news. The matter of Proposition 8 should be resolved thoughtfully and without delay,” Brown said in a statement.

Both opponents and supporters of Proposition 8 expressed confidence Wednesday that their arguments would prevail. But they also agreed that the cases present the court’s seven justices - six of whom voted to review the challenges - with complex questions that have few precedents in state case law.

Although more than two dozen states have similar amendments, some of which have survived similar lawsuits, none were approved by voters in a place where gay marriage already was legal.

Neither were any approved in a state where the high court had put sexual orientation in the same protected legal class as race and religion, which the California Supreme Court did when it rendered its 4-3 decision that made same-sex marriage legal in May.

Opponents of the ban argue that voters improperly abrogated the judiciary’s authority by stripping same-sex couples of the right to wed after the high court earlier ruled it was discriminatory to prohibit gay men and lesbians from marrying.

“If given effect, Proposition 8 would work a dramatic, substantive change to our Constitution’s ‘underlying principles’ of individual equality on a scale and scope never previously condoned by this court,” lawyers for the same-sex couples stated in their petition.

The measure represents such a sweeping change that it constitutes a constitutional revision as opposed to an amendment, the documents say. The distinction would have required the ban’s backers to obtain approval from two-thirds of both houses of the California Legislature before submitting it to voters.

Over the past century, the California Supreme Court has heard nine cases challenging legislative acts or ballot initiatives as improper revisions. The court eventually invalidated three of the measures, according to the gay rights group Lambda Legal.

Andrew Pugno, legal counsel for the Yes on 8 campaign, said he doubts the court will buy the revision argument in the case of the gay marriage ban because the plaintiffs would have to prove the measure alters the state’s basic governmental framework.

Joel Franklin, a constitutional law professor at Monterey College of Law, said that even though the court rejected similar procedural arguments when it upheld amendments reinstating the death penalty and limiting property taxes, those cases do not represent as much of a fundamental change as Proposition 8.

“Those amendments applied universally to all Californians,” Franklin said. “This is a situation where you are removing rights from a particular group of citizens, a class of individuals the court has said is entitled to constitutional protection. That is a structural change.”

The trio of cases the court accepted were filed by six same-sex couples who have not yet wed, a Los Angeles lesbian couple who were among the first to tie the knot on June 16 and 11 cities and counties, led by the city of San Francisco.