SACRAMENTO -- Government reform groups lashed out Monday at a ballot initiative that claims its intent is to eliminate special interest money from Sacramento.

At a news conference, leaders from Common Cause California and League of Women Voters said that Proposition 32, dubbed "Stop Special Interest Money Now," is an age-old assault on union power dressed up as campaign finance reform.

"It's not at all what it seems," said Trudy Schafer, of the state League of Women Voters. "It promises political reform but it's really designed by its special interest backers to help themselves and harm their opponents."

The measure was written by a core group of Orange County Republicans who have failed in three statewide campaigns to restrict labor unions' ability to collect members' dues for political purposes. This time, they've attempted to broaden their appeal by seeking to ban corporate and union donations to candidates and campaigns -- in addition to forbidding unions from collecting dues for campaigns.

But opponents said Proposition 32 will not take money out of politics because so-called super PACs and independent expenditure groups will still be allowed to spend unlimited money -- and will likely become even more predominant in campaigns.

In addition, a whole class of major commercial enterprises that are not considered corporations but have similar resources would be exempt from the measure's restrictions, opponents said. The bill does not apply to limited liability companies (LLCs) like Wall Street investment firms, hedge funds, real estate developers and others, and it specifically exempts insurance companies from the payroll deduction ban, opponents said.

"I'm all for campaign finance reform," said Derek Cressman, western regional director for Common Cause. "I've spent the last 15 years of my life working for campaign finance reform. I know campaign finance reform, and, friends, Prop. 32 is not campaign finance reform."

Bankrolling the measure are a number of investors, CEOs and other wealthy individuals such as Palo Alto's Thomas Siebel, the chairman of the First Virtual Group, who has contributed $500,000.

Still, labor groups view the ballot measure as a deadly threat and have far outpaced supporters in the money chase. Since the most recent finance reports on April 30, they've added $3.4 million to the $3.9 million cash they had on hand for a total of $7.3 million. The Yes side has $1.9 million.

Proponents said there are no exemptions written into the measure, but that it defines corporations as defined under federal and state laws.

"Individuals can give," said Jake Suski, spokesman for the Yes on Proposition 32 campaign. "Prop. 32 is designed to allow individuals to have a stronger voice. And it empowers union members by allowing them to have a direct say over whether their money goes to political causes.

"Opponents want to talk about what the initiative doesn't do because they'll say or do anything that protects the status quo."

Less empowered individuals like teachers need their unions to add a collective voice to the political dialogue, said Lisa Sussman, an Auburn second grade teacher who is politically active with the California Teachers Association.

"It is grossly unfair that corporate special interests want to silence my voice," she said. Proposition 32 "does nothing to fix Sacramento's problems. Its loopholes would only allow the wealthy pushing this attack to increase their influence."

Contact Steven Harmon at 916-441-2101. Follow him at Twitter.com/ssharmon. Read the Political Blotter at IBAbuzz.com/politics.