The effort to repeal last year's voter-approved gay marriage ban in California that began on November 16 is looking less likely to reach the ballot box in 2010 after the state's largest grassroots organization withdrew its support on Monday.

Rick Jacobs, founder of the 70,000-member Courage Campaign, called for more time to “change hearts and minds before returning to the ballot to restore marriage for gay and lesbian couples.”

“We are taking the lessons learned from last year's Prop. 8 campaign, the campaigns in Maine and other states to understand the fundamental work that must be done before moving forward in California,” Jacobs said in a statement.

In August, Equality California, the group that led the unsuccessful opposition to Proposition 8 last year and the state's largest gay rights group, said it planned to wait three years before returning to the polls.

We support “helping the community win a ballot initiative to restore marriage at the November 2012 election,” Geoff Kors, executive director of the group, said in a statement.

At the time, Jacobs disagreed with Kors, telling the Wall Street Journal: “I don't know why we would say no to the movement we've got now.”

But Jacobs' own polling and other research his organization commissioned appears to have changed his mind.

“We also must come together as a community to create a broad coalition and governance structure, put in place a strong manager and secure the resources to win. Right now, the pieces are not all in place to do so confidently,” he said.

In announcing its decision, Equality California said it was concerned about returning to big donors so soon after Proposition 8 had devoured nearly $80 million from both sides of the debate.

The group Love Honor Cherish, a coalition of smaller gay rights groups, is heading the effort to gather the nearly 1 million signatures needed to qualify a gay marriage question for the November, 2010 ballot.