A controversial California ballot measure that would fund a decade of stem cell research with $3 billion in state money was headed for a resounding victory on Wednesday, initial returns showed.

The initiative, which was endorsed by popular California Gov. Arnold Schwarzenegger in a move that put him at odds with his Republican party and the Bush administration, was carrying 59 percent of the vote with about 74 percent of precincts reporting.

Backers of the measure say the funding program would jump start scientific work that could help cure diseases and establish California as a hub for leading-edge research on a par with Singapore and Britain.

The stem cell measure had been closely watched nationally, and attracted even wider attention after the sudden death of paralyzed actor and stem cell research advocate Christopher Reeve.

Meanwhile, actor and “Passion of the Christ” filmmaker Mel Gibson came out against the measure, which had also been opposed by the Catholic church and groups that argued it would divert money from more urgent causes.

The California ballot initiative would establish a pool of money that would dwarf other U.S. public funding for such research.

The measure, known as Proposition 71, would float $3 billion in tax-exempt bonds to set up an Institute for Regenerative Medicine and fund 10 years of research.

It would also establish a constitutional right within California to conduct stem cell research while outlawing research on reproductive cloning.