California voters support efforts to reform the state’s century-old process for ballot referendums, with Republicans and Democrats in rare agreement over a proposal pushed by labor unions and good-government groups to increase transparency around campaigns to overturn state laws.

A UC Berkeley Institute of Governmental Studies poll co-sponsored by The Times found more than three-quarters of registered voters — including 7 in 10 Republicans — support changes. Those include disclosing the top three funders of a referendum campaign on each page of a petition, making signature gatherers attest under penalty of perjury that they didn’t lie to voters and suspending the licenses of those who knowingly mislead voters.

By similar margins, voters across party lines support calls to simplify ballot descriptions to make it easier to understand if a referendum upholds or reverses a law and to list the top three donors in support and opposition in the official summary of a measure.

“There’s overwhelming support to clean up what I would call a broken referendum system,” said Tia Orr, executive director of SEIU California.

Lawmakers are considering those changes and others at the state Capitol this year under Assembly Bill 421. The Assembly approved the bill Wednesday and sent it to the state Senate.

Led by Orr and the Service Employees International Union, advocates for the bill allege companies have been lying to voters about the intent of signature gathering campaigns as part of a political tactic to stall, and occasionally reverse, progressive laws passed by Democrats who control the state Legislature.

Their frustrations mounted this year after companies successfully qualified initiatives for the 2024 ballot that seek to overturn a state environmental law to create buffer zones between new oil wells and homes and schools as well as legislation backed by unions that would improve wages and working conditions for fast food workers.

In both campaigns, California voters have shared stories of being lied to and misled about the effect of their signature.

To get a measure on the ballot that would reverse a law, backers of a referendum must obtain valid signatures from 5% of the number of voters in the last gubernatorial election. Political campaigns often hire firms that pay people per signature to circulate petitions outside grocery stores and retail chains and on college campuses.

The referendum process was established in 1911 to provide Californians with a mechanism through direct democracy to counter the influence corporations held over state government. But now that Democrats make up more than two thirds of an increasingly progressive California Legislature, companies are spending millions of dollars to take advantage of the referendum process more often.

The bill to change the process would require that 5% of all signatures collected to qualify a measure be gathered by volunteers. That’s aimed at making it harder for companies to rely exclusively on paid signature gatherers, who are often from out of state, to push measures that lack grassroots support.

The poll found that 50% of voters supported changing state law to require that unpaid volunteers participate in signature collection, compared to 15% opposed and 35% who had no opinion.

Assembly Republican Leader James Gallagher (R-Yuba City) said Democrats and their union allies are trying to create barriers to using direct democracy because they don’t like the fact that their marquee measures will go before voters next year.

“I find it interesting when the direct democracy process seems to work for the other party, they’re fine with it,” Gallagher said during floor debate on the bill. “But when it doesn’t work, all of a sudden there are reforms and changes that need to be done.”

The Berkeley IGS poll was administered online in English and Spanish May 17-21 among 7,465 California registered voters. The poll sample was weighted to match census and voter registration benchmarks. Because of weighting, precise estimates of the margin of error are difficult, but the results are estimated to have a margin of error of 2.5 percentage points in either direction for the full sample.

Funding for the poll questions regarding the referendum process came from the Evelyn and Walter Haas, Jr. Fund, a private foundation based in San Francisco that aims to increase civic participation and improve the state’s democratic processes.