A proposal to raise taxes on the wealthiest Californians has qualified for the November ballot, state officials said Wednesday, setting up what could be an expensive and divisive fight.

The so-called billionaire tax — which has divided Democrats in the state — would implement a one-time tax on rich Californians if approved by voters.

California Secretary of State Shirley Weber said in a statement late Wednesday that the measure was eligible for the ballot this fall after her department verified the required number of signatures submitted by organizers.

There is still a chance, however, that the initiative will not appear on California’s ballot. The proposal’s supporters — led by Service Employees International Union-United Healthcare Workers West, a large California healthcare workers union — have until June 25 to decide whether they want to move forward with their push.

Several groups and lawmakers have for months engaged in negotiations over ways to reach a deal that would appease the unions supporting the tax while also preventing it from appearing on the ballot.

The measure has split prominent Democrats across the state.

Opponents have argued the initiative would drive wealthy investors and tech leaders from the state. California Gov. Gavin Newsom, widely seen as a presidential hopeful, has lined up in opposition to the billionaire tax.

Former Health Secretary Xavier Becerra, the leading candidate to succeed Newsom as governor, also opposes the tax.

On the other side, Rep. Ro Khanna, who also has his eye on a future White House bid, and Tom Steyer, a billionaire activist who ran unsuccessfully for governor, have backed the effort, arguing that it would help close income inequality gaps. Proponents have also made the case that it will help make up for state budget shortfalls as a result of Medicaid cuts in the “big, beautiful bill” that President Donald Trump signed into law last year.

The initiative would implement a one-time 5% tax on the assets of Californians whose net worth exceeds $1.1 billion. It would require the state to spend 90% of the new revenue on healthcare, with the remaining 10% split between education and food assistance programs. That discrepancy angered a number of Democratic groups advocating for education and food assistance.

In addition to the one-time tax on those worth more than $1.1 billion, it would implement a smaller tax on individuals worth between $1 billion and $1.1 billion. The taxes would apply retroactively to anyone living in the state as of Jan. 1, 2026.