Mr. Garamendi named Allstate, Safeco, State Farm, Farmers and 21st Century as the companies engaged in the alleged blackmail effort.

The commissioner is currently engaged in an effort to win the Democratic nomination for lieutenant governor in the June primary and said the threatened $2 million anti-reform ad campaign was an attempt to derail his race.

A group called California to Stop Unfair Rate Increases [CSURI] has said that it has approached the companies Mr. Garamendi named to spearhead a “more expansive effort to educate and engage Californians before it's too late.”

CSURI spokesman Rick Claussen denied any blackmail effort. “It is unfortunate that Commissioner Garamendi is distracting from the real issues of the effort, which is to educate Californians about impending, unfair auto insurance rate increases by making baseless and inflammatory accusations that are completely untrue,” he said.

None of the companies mentioned by Mr. Garamendi responded to a request for comment, but Safeco referred the inquiry to CSURI.

The Garamendi press conference came in response to the announcement by CSURI that it will begin its education campaign through television ads and mailings about “proposed auto insurance regulations that will unfairly raise rates for millions of drivers statewide.”

Mr. Garamendi said his rate revisions will be a final implementation of the voters' will as expressed through Proposition 103 passed in 1988. “The new rules will reward those who drive safely in rural areas as well as urban areas,” he said. “And they will put an end to the unfair insurance industry practice of charging a good driver who lives in one ZIP code more than a good driver who lives across the street in another ZIP code.”