The Los Angeles Times is reporting that California Attorney General Jerry Brown has reversed course and will seek to have Proposition 8 – the constitutional amendment approved by a slim majority of California voters in November that bans gay marriage – invalidated.

Previously, Brown has said he would defend the measure.

But in a filing to the state Supreme Court on Friday, Brown called for the defeat of the gay marriage ban, saying it “deprives people of the right to marry, an aspect of liberty that the Supreme Court has concluded is guaranteed by the California Constitution.”

“Proposition 8 must be invalidated because the amendment process cannot be used to extinguish fundamental constitutional rights without compelling justification,” he wrote. The filling came in response to three lawsuits filed by gay rights groups, along with the cities of Los Angeles and San Francisco.

“It's outrageous,” Frank Schubert, campaign manager for Yes-on-8, told the Times.

Gay rights activist were clearly elated by the turn of events. “His position demonstrates that he is a leader of courage and conviction,” said Equality California Executive Director Geoff Kors, who initially ran the campaign to defeat the measure.

“We are very pleased that upon review of the law, he has moved from his previous statements that he would defend Prop 8,” Kors said in a statement.

Proponents of Proposition 8 also surprised with the news that they had recruited Kenneth Starr, dean of Pepperdine University's law school, to serve as lead counsel. Starr will argue their case to the state Supreme Court.

Starr is the former independent counsel who investigated President Bill Clinton in the Whitewater affair, which led to the impeachment of Clinton in the House. The Senate, however, acquitted him.

Pepperdine Law School is making a habit of defending Proposition 8. Associate Professor of Law Richard Peterson appeared in two pro-Prop 8 advertisements throughout the campaign.

In their filing, Proposition 8 proponents also revealed that they were seeking to nullify thousands of gay and lesbian marriages performed during the May-to-November period when gay marriage was legal in the state.

They wrote: “Proposition 8's brevity is matched by its clarity. There are no conditional clauses, exceptions, exemptions, or exclusions: 'Only marriage between a man and a woman is valid or recognized in California.'”

“Its plain language encompasses both pre-existing and later-created same-sex (and polygamous) marriages, whether performed in California or elsewhere. With crystal clarity, it declares that they are not valid or recognized in California.”

Gay groups called the idea of stripping away legal gay marriages “mean-spirited.”

“The motivation behind this mean-spirited and heart-breaking action should not be allowed to be buried in legal brief,” Rick Jacobs, founder of the Courage Campaign, a grassroots group that ran several anti-Proposition 8 ads independently of the official No-on-8 campaign, told CNN. “If Proposition 8's sponsors plan to destroy lives, they should at least have the courage to admit it publicly.”

Gay rights groups filed three lawsuits challenging the validity of the gay marriage ban on November 5, the day after Election Day. They argue that Proposition 8 is a revision of the California Constitution. A constitutional revision requires Legislative action before being sent to the voters. Proposition 8 was placed on the ballot by voter petition and is therefore illegal, say gay marriage backers. Gay marriage opponents disagree.

“Petitioners' challenge depends on characterizing Proposition 8 as a radical departure from the fundamental principles of the California Constitution,” they wrote. “But that portrayal is wildly wrong. Proposition 8 is limited in nature and effect. It does nothing more than restore the definition of marriage to what it was and always had been under California law before June 16, 2008 – and to what the people had repeatedly willed that it be throughout California's history.”

Protesters in California, made up of grassroots gay activists and their allies, have been demonstrating against the gay marriage ban, and the churches that heavily endorsed it, since its passage on November 4. What influence, if any, their actions will have on the court's decision remains to be seen. The California Supreme Court is scheduled to hear arguments in March.