A U.S. federal appeals court on Tuesday ruled Proposition 8, the voter-approved ban on same-sex marriage in California, unconstitutional, paving way for the U.S. Supreme Court to rule on the issue as early as next year.

According to the court document, a three-judge panel of the U.S. 9th Circuit Court of Appeals in San Francisco ruled 2-1 that Proposition 8, the 2008 ballot ban that makes only marriage between a man and a woman is valid or recognized in California, violated the U.S. Constitution.

The court said: "Proposition 8 serves no purpose, and has no effect, other than to lessen the status and human dignity of gays and lesbians in California, and to officially reclassify their relationships and families as inferior to those of opposite-sex couples."

According to the judges, same-sex marriage will not resume in the state until Proposition 8 backers pass the deadline to appeal. If an appeal is filed, the same-sex marriage in California will not resume until it is resolved.

The architects for Proposition 8 have vowed to appeal to a large panel of the court or the U.S. Supreme Court.

Tuesday's ruling upheld a decision by former Chief U.S. District Judge Vaughn Walker, who presided over the nation's first federal court trial on same-sex marriage. He ruled in 2010 that gays and lesbians have a constitutional right to marry their chosen partner. The ruling, if upheld on appeal, would apply nationwide in the U.S.

In another ruling, the court also refused to invalidate Walker's ruling. After he retired, Walker disclosed he was in a relationship with a man for 10 years. He has been accused of being biased when he made the ruling.

Same-sex couples were legal to marry in California for six month after the California Supreme Court struck down a ban in May 2008, but voters passed Proposition 8 in November 2008.