Backers of California’s controversial billionaire tax initiative on Thursday publicly challenged Gov. Gavin Newsom to support a scaled-back version of the proposal — arguing a one-time levy on the state’s wealthiest residents is needed to prevent what they called a looming health-care crisis.

In an open letter to the governor, the Billionaire Tax Now Coalition — sponsored by labor union Service Employees International Union-United Healthcare Workers West — offered to reduce the proposed tax from 5% to 2% if Newsom agrees to support the measure as a temporary solution to offset deep federal healthcare cuts.

“We are prepared to join you in enacting a 2% version of our initiative instead of the original 5% version,” the coalition wrote.

The proposal officially qualified for California’s November ballot this week after state election officials verified enough petition signatures.

As originally written, the initiative would impose a one-time 5% tax on California residents whose net worth exceeded $1 billion as of Jan. 1, 2026. Supporters estimate the measure would generate $100 billion from roughly 200 billionaires, with 90% of the revenue dedicated to healthcare spending and the remainder directed to education and food assistance programs.

The coalition, led by SEIU-UHW, says the tax is necessary to backfill health-care funding losses stemming from President Trump’s tax and spending package, known as the “One Big Beautiful Bill Act.”

The California Department of Health Care Services has projected the federal changes could cost the state roughly $30 billion annually. About 14 million Californians rely on Medi-Cal.

Download The California Post App, follow us on social, and subscribe to our newsletters

In the letter, the coalition said a reduced 2% levy would serve as a two-year bridge while California develops a longer-term funding strategy. The group argued the tax could prevent 150,000 health-care job losses, avert hospital and clinic closures and preserve coverage for 3.2 million Californians. It also warned that more than 20 million residents could face higher premiums, deductibles and co-pays if lawmakers fail to act.

“When hospitals are closed and costs are shifted to working families, patients die,” the coalition wrote. “These aren’t abstractions; they’re preventable deaths.”

Newsom has consistently opposed tax increases during his tenure and has warned that higher taxes could drive wealthy residents and businesses out of California.

Opponents of the measure, including Silicon Valley donors and business groups, argue a wealth tax would accelerate the departure of high-net-worth individuals from a state already heavily reliant on top earners for tax revenue.

The initiative’s sponsors have until June 25 to withdraw the measure from the ballot.