Google co-founder Sergey Brin is backing two ballot initiatives designed to block a proposed billionaire tax on California residents with assets exceeding $1 billion ahead of the November election. The measures, sponsored by the group Building a Better California, would prohibit new taxes on certain financial assets and increase audits of taxpayer-funded programs.

The initiatives aim to counter a 5% levy on personal financial assets, excluding real estate, that has sparked debate across the state. The first measure would ban new taxes on personal property such as retirement accounts, intellectual property, and other financial assets, and would prevent such taxes from being applied retroactively. The second initiative would mandate more rigorous financial and performance audits of programs financed by new tax revenues and contains provisions that would effectively invalidate the billionaire tax.

Building a Better California has received substantial financial support from Brin, contributing $57 million, alongside $36 million from other billionaires and business leaders. According to the group’s spokesperson, Abby Lunardini, the initiatives are intended to enhance government accountability, protect California’s economy, and prioritize affordability and quality of life. She emphasized support for public investments in housing, infrastructure, and education while calling for greater safeguards on tax dollars.

Both measures have secured more than enough signatures to qualify for the November ballot, with around 1.4 million and 1.5 million signatures respectively. Polling data shared with a California-based news outlet indicates strong voter support: approximately 74% favor adding financial and performance audits for taxpayer-funded programs, and a similar majority support prohibiting new taxes on specified financial assets.

Opposing the countermeasures is a union-backed billionaire tax initiative, which aims to address funding shortages in state health care, particularly those resulting from cuts to Medicaid and federal support programs. This initiative had amassed roughly 1.5 million signatures as of last week.

Under California law, if competing ballot propositions pass, the one receiving the most affirmative votes prevails. Current polls suggest about half of likely voters support the proposed wealth tax. Governor Gavin Newsom has voiced opposition, expressing concerns that the levy would prompt wealthy residents and entrepreneurs to leave the state. The upcoming election will determine whether the billionaire tax or the competing measures backed by Brin and other business leaders will take effect.