California voters will consider a controversial proposal in November to temporarily raise taxes on billionaires after the labor union backing the measure announced Thursday it would forge ahead despite pressure from critics to withdraw it.

The proposal, backed by the Service Employees International Union Healthcare Workers West, would impose a one-time 5% tax on individuals whose net worth exceeds $1 billion and who were living in the state as of Jan. 1, 2026. The goal is to generate $100 billion in revenue, mainly to fund the state’s Medicaid system after federal cuts.

“I am all in on this,” union President Dave Regan said on a Zoom call, adding that opponents of the proposal are “totally out of touch.”