California's ban on gay marriage has been overturned by a federal court, potentially putting the thorny issue on a legal track that could eventually arrive at the U.S. Supreme Court.

While many conservative Americans continue to fight against weddings for gay couples, Wednesday's ruling by Chief U.S. District Judge Vaughn Walker received widespread support from rights advocates and their supporters.

Outside of the federal court where Walker delivered his ruling in San Francisco, a large crowd gathered to celebrate the news.

California Gov. Arnold Schwarzenegger added his voice to the praise, calling the ruling a step toward freedom and equality.

Walker's ruling comes after a lawsuit was filed by two gay couples who stated that their constitutional rights had been violated by the ban, which was approved by California voters.

Former U.S. Solicitor General Theodore Olson delivered the closing arguments in the case, and he said the ruling "vindicates the rights of a minority of our citizens to be treated with decency and respect and equality in our system."

Conversely, a conservative umbrella group called Protect Marriage said that it would appeal Wednesday's ruling to the 9th U.S. Circuit Court of Appeals.

"In America, we should uphold and respect the right of people to make policy changes through the democratic process, especially changes that do nothing more than uphold the definition of marriage that has existed since the founding of this country and beyond," said defence lawyer Jim Campbell, who works with the group.

While gay couples and supporters in major U.S. cities celebrated the legal victory, it does not allow same-sex marriages to legally resume.

According to Judge Walker, both sides will have until Friday to submit new arguments about whether the ruling should hold, despite the likelihood that a new appeal will be launched.

The case pits civil rights against a publicly approved ban, and if the 9th U.S. Circuit Court of Appeals agrees to hear the case, the next step would be the halls of the U.S. Supreme Court.

In mid 2008, the California Supreme Court legalized gay marriage, and soon after, 18,000 gay couples rushed to the altar.

However, five months after the high court ruling, California narrowly passed Proposition 8 though a divisive vote, putting the weddings to an end.

With each legal battle, the case gains more significance: first it was a state case, now it is a federal one that could have sweeping results throughout the country.

Still, supporters of Proposition 8 maintain that the ban is necessary to safeguard traditional marriage and childbearing.

However, Judge Walker wrote that the ban violated both due process and equal protection clauses.

Additionally, Walker wrote in his 136-page ruling that the ban fails "to advance any rational basis in singling out gay men and lesbians for denial of a marriage license."

"Indeed, the evidence shows Proposition 8 does nothing more than enshrine in the California Constitution the notion that opposite-sex couples are superior to same-sex couples."