A 3-judge panel on Tuesday ruled Proposition 8, California's gay marriage ban, is unconstitutional.

The Ninth Circuit Court of Appeals handed down its long-awaited decision to the cheers of gay marriage supporters. However, supporters of Proposition 8 will most likely appeal the decision to the United States Supreme Court. That means another lengthy wait for engaged gay and lesbian couples in California.

The court upheld now-retired U.S. District Judge Vaughn R. Walker's 2010 ruling which said Proposition 8 violates the constitutional rights of gay couples who wish to marry.

“Because Proposition 8 prevents California from fulfilling its constitutional obligation to provide marriages on an equal basis, the court concludes that Proposition 8 is unconstitutional,” Walker wrote.

Co-counsel David Boies had previously described Walker's 138-page ruling as “difficult to overturn on appeal,” because an appeals court must weigh its decision on the trial court's factual findings.

Walker heard 13 days of testimony during a January trial held in a San Francisco courtroom and concluded that “[T]he evidence shows that, by every available metric, opposite-sex couples are no better than their same-sex counterparts; instead, as partners, parents and citizen, opposite-sex couples and same-sex couples are equal.”

California voters approved the measure by a narrow margin on November 4, 2008. The law put an end to the weddings of gay couples taking place in the state after the California Supreme Court legalized the institution.

Supporters of marriage equality have planned events and rallies across California.