(CNN) -- An appeals court ruling temporarily blocking same-sex marriages from resuming in California drew strong reactions from opponents and supporters of the state's controversial 2008 referendum on the issue.

Couples hoping to marry rushed to cancel their plans after an order from the 9th Circuit Court of Appeals late Monday set aside a federal judge's decision earlier this month that would have permitted same-sex marriages to resume in California as early as Wednesday.

And advocates on both sides of the issue said they were prepared to make their arguments in court.

"This delay is just really going to screw us up," said Harry Seaman, who was planning to marry his boyfriend Friday afternoon.

Friends and family had already been invited to celebrate, he said.

"We got the first appointment we could get," he said. "I knew something was going to happen, but I just didn't know it was going to happen before we even got a chance."

The appeals court Monday set a fast schedule to hear the merits of the constitutional challenge to Proposition 8, the 2008 initiative defining marriage as only between one man and one woman.

Oral arguments will now be held the week of December 6, meaning a decision on whether same-sex couples can legally wed likely will not be decided until sometime next year.

Andy Pugno, an attorney representing supporters of Proposition 8, said California's voters should be happy about Monday's ruling.

"We just think today is a good day for the voters in general, to see the vote of the people actually upheld, even though it's not the final word yet," he told CNN affiliate KCRA. "We still have appeals to go through, but for the time being the vote of the people has been upheld."

Opponents of Proposition 8 said they were disappointed by the ruling, but planned to continue their fight.

"Every additional day that couples must wait to marry again in California is painful, but despite the terrible disappointment for the many couples whose right to marry has been delayed yet again, today's ruling includes another significant victory for our side," Kate Kendell, executive director of the National Center for Lesbian Rights, said in a statement. "The court did the right thing by putting the case on a fast track and specifically ordering that Prop 8 proponents show why they have a legal right to appeal."

Opponents of Proposition 8 will not appeal Monday's ruling to the U.S. Supreme Court, according to spokesman Yousef Robb with the American Foundation for Equal Rights. Opponents could ask the Supreme Court to intervene on the narrow question of whether to allow the stay to be lifted, but both sides of the debate agree the odds of the justices getting involved at this stage are very slim.

The case has had an up-and-down series of rulings and referendums. The state's high court had allowed same-sex marriage, but then the voter referendum two years ago passed with 52 percent of the vote. The California Supreme Court subsequently allowed that initiative to stand, saying it represented the will of the people.

Opponents of the law next filed a federal challenge, saying the law violated 14th Amendment constitutional protections of due process and equal protection.

Judge Vaughn Walker on August 4 agreed, ruling that the voter-approved ban on same-sex marriage violated federal civil rights laws.

His 136-page opinion concluded that Proposition 8 "fails to advance any rational basis in singling out gay men and lesbians for denial of a marriage license." The Reagan-appointed judge added, "Proposition 8 does nothing more than enshrine in the California Constitution the notion that opposite-sex couples are superior to same-sex couples."

Same sex marriage is currently legal in five states and in the District of Columbia, while civil unions are permitted in New Jersey. The five states are Massachusetts, Connecticut, Vermont, Iowa, and New Hampshire.

Walker's landmark ruling assured a swift federal appeal that ultimately may reach the Supreme Court. One sticking point could be whether Proposition 8 supporters in court -- all private citizens and groups -- have legal "standing" to continue appealing the case. State officials, including the governor and attorney general, support individual same-sex couples challenging the law. Such state "actors" traditionally defend voter referendums and legislation.

Some legal experts say if the appeals court eventually rules Proposition 8 backers cannot bring their petition for relief, the Supreme Court may not seek to intervene further, giving no clear guidance on the larger question of the constitutionality of same-sex marriage nationwide. The high court, in a 1997 unrelated appeal, had expressed "grave doubts" about the ability of such private groups to challenge rulings that strike down ballot initiatives.

Walker's ruling had given the losing side a chance to appeal, and he held off allowing same-sex marriages from resuming until an emergency injunction request could be decided by the higher court.

Among the federal appeals judges who agreed Monday to block same-sex marriages from resuming immediately was Sidney Thomas, a Montana native who was interviewed this spring by President Obama for the Supreme Court vacancy that eventually went to Elena Kagan.

CNN's Bill Mears and Matt Cherry contributed to this report.