In what could prove to be one of the most expensive political slugfests of the Nov. 4 general election, a San Francisco-based utility has recently donated a cool $12 million to an effort to see that Prop. 7 is defeated.

Add in an extra $10 million from Pacific Gas & Electric's counterpart to the south, Rosemead-based Southern California Edison, plus $1.7 million in assorted prior donations and you get a total of $23.7 million being spent so far by Golden State utility companies to kill a ballot measure which Field Poll researchers said recently was being favorably viewed by California voters.

Specifically, Prop. 7 would require all California utilities to generate at least half of their power from alternative sources, such a wind or solar, by 2025. The power companies are already required to provide 20 percent of energy from renewable sources by 2010.

Southern California Edison representatives recently told the Sacramento Bee that, if approved, the measure "would upend the existing regulatory process, disrupt existing renewables development, significantly raise rates and threaten reliability."

Supporting the measure is Peter Sperling, son of Arizona billionaire and University of Phoenix founder John Sperling. Sperling, to date, has donated $3 million to promote Prop. 7's passage.

Jim Gonzalez, a former San Francisco supervisor and current Sacramento-based political strategist, has funneled $100,000 to help the measure pass as well. Gonzalez is the initiative's primary spokesman.