The California insurance commissioner Tuesday said he would defend in court his decision to require Mercury Insurance Co., to reduce its homeowners-insurance rates in the state effective in June.

The suit is the latest in a string of enforcement actions, voter initiatives, and court challenges pitting Mercury General and its chairman, George Joseph, against Consumer Watchdog and its head, Harvey Rosenfeld.

The most recent statement by Dave Jones, California’s insurance commissioner, was prompted a suit filed March 1 by Mercury in state Superior Court in Sacramento.

The Mercury filing asks the court to vacate Jones’ Feb. 11 order requiring the company to reduce its homeowners’ rates by 8.18 percent.

Instead, Mercury asked the court to allow it to raise its rates by 7.3 percent. 

According to Consumer Watchdog officials, the suit delays implementation of 8.18 percent homeowners’ insurance rate cut Jones ordered until after the litigation is resolved.

In a statement, Consumer Watchdog says it will seek to be a party to the Mercury lawsuit.

“As a result of the suit, the $16 million in savings due to Mercury homeowners policyholders will be delayed, and customers of the company will be overpaying for insurance as long as the case is outstanding,” Consumer Watchdog officials say in a statement.

“Mercury Insurance was given ample opportunity to justify its requested rate hike, but at the end of the day, the commissioner properly ordered a decrease in accordance with the law and the weight of the evidence,” says Consumer Watchdog’s Litigation Director Pamela Pressley.

 “Even though Mercury Casualty’s homeowners’ premiums are among the lowest in the state, the commissioner, based on outdated data, adopted an administrative law judge’s decision that Mercury Casualty’s rates for its homeowners’ line of insurance overall must be decreased even further by approximately 5 percent,” Mercury alleges in court papers.

In a comment following Jones’ statement, Mercury adds, “Mercury’s insurance rates are among the most competitive in California—as exemplified by our 97 percent renewal rate on homeowners policies. We are therefore disappointed in the commissioner’s ruling, and though we don’t comment on pending litigation, Mercury looks forward to correcting the commissioner’s position.” 

Jones’ order was based on a decision by state Administrative Law Judge Kristin L. Rosi that followed a 2012 public hearing requested by Consumer Watchdog. The consumer group contended that Mercury’s original proposal for an overall 8.8 percent rate increase was excessive and improper.

Among the issues Consumer Watchdog lawyers are concerned about is $922,000 in 2008, 2009 and 2010 political contributions and lobbying expenses Mercury seeks to include in its costs for providing homeowners insurance in California. 

Jones said in a statement that the reduced rates would impact approximately 270,000 homeowners in California, saving them more than $16.5 million.

Jones said he made his decision based on evidence presented during a public hearing. 

“I have directed the Department of Insurance to vigorously defend against Mercury’s effort to deprive homeowners of this rate decrease,” Jones said.