Updated

An effort to overturn a new law allowing transgender students to choose which school restrooms they use and whether to play boys or girls sports got a boost Friday when a major player in the passage of California's now-defunct same-sex marriage ban threw its support behind the campaign.

The National Organization for Marriage announced it was working with another conservative group, the Capitol Resource Institute, to repeal the law at the ballot box. The marriage group provided early fundraising and organizing for the 2008 ballot initiative that outlawed same-sex marriages, known as Proposition 8.

Opponents of the transgender student law have until Nov. 8 to gather the signatures of 504,760 registered voters needed to place a referendum on the November 2014 ballot to nullify the statute.

The National Organization for Marriage is encouraging its members to help circulate petitions and to give money that could be used to hire professional signature-gatherers.

The political strategist who ran the successful Proposition 8 campaign, Frank Schubert, has signed on to manage the referendum campaign. Noting that no one has ever qualified a referendum in California using only volunteers, Schubert said "it's a virtual certainty" the campaign will hire paid petition-circulators to supplement work already going on at churches statewide.

"We are actively talking with donors about helping to fund that," said Schubert "A referendum is a very hard thing to do. It's definitely an uphill thing."

After passage of Proposition 8, Schubert led a successful campaign a year later to block same-sex marriages in Maine. Last November, he oversaw four unsuccessful efforts to keep gay unions from being legalized in Maine, Maryland, Minnesota and Washington.

California last month became the first state to spell out the rights of transgender K-12 students in state law when Gov. Jerry Brown signed AB1722. The statute requires public schools to allow students to participate in sex-segregated programs, activities and facilities based on self-perception of gender instead of birth gender or transition status.

Supporters said the law will help reduce bullying and discrimination against transgender students. Families of transgender students have been waging battles with school districts across the country over what restrooms and locker rooms their children can use. The disagreements have sometimes landed in court.

Equality California Executive Director John O'Connor, whose organization co-sponsored AB1722 and helped lead the campaign to defeat Proposition 8 in 2008, said civil rights groups were closely watching and would be ready to respond if the proposed referendum makes the ballot.

"Frank Schubert has built a political career on these anti-LGBT measures that divide people and perhaps years ago he had some success," O'Connor said. "We have turned the corner. The public is solidly in favor of LGBT equality now."

Schubert said qualifying the referendum for the ballot will be difficult, but he thinks it would pass easily if put before voters.

"This is not a law people support by a long-shot," he said. "This is an attempt to hijack an issue that may be legitimate for a small number of people and use it to impose a statewide mandate in pursuit of a larger political agenda ... to strip society of all gender norms so there is no difference between men and women."