SACRAMENTO, Calif. (Legal Newsline)-The California governor's race turned especially ugly Monday, with state Insurance Commissioner Steve Poizner calling for state and federal investigations of his rival in the Republican primary.

Poizner has asked the state attorney general's office, the California secretary of state, the U.S. attorney's office and the FBI to investigate GOP frontrunner Meg Whitman over e-mails that her top campaign strategist sent to his campaign.

In letters to officials, Poizner said the e-mails sent by Whitman strategist Mike Murphy "could threaten the integrity of the electoral process."

In one of the missives, Murphy urged a Poizner pollster to try to get Poizner to bow out of his campaign against Whitman and instead challenge U.S. Sen. Dianne Feinstein, D-Calif., when she's up for reelection in 2012.

"Is there anything we can do to get SP to reconsider this race?" Murphy wrote. "I hate the idea of us each spending $20 million beating on the other in the primary, only to have a damaged nominee. And we can spend $40 million+ tearing up a guy with great future statewide potential."

On Monday, Poizner lashed out at Murphy's effort.

"This is an attempt behind the scenes to try to get me not to run," Poizner said. "You can't threaten people to get out. You can't manipulate people to get out. Voters have to have choices."

Whitman and Poizner are both former Silicon Valley executives who have contributed heavily to their respective campaigns.

For his part, Murphy acknowledged e-mailing the Poizner adviser Jan van Lohuizen.

"It is true that I have been trying to find a way to avoid a costly and unnecessary Republican primary. I believe it is important that Republicans across California unite around Meg Whitman to defeat Jerry Brown in the fall. It is also true that I am not the only one with this view," Murphy said. "Hopefully, the commissioner was not serious about wasting taxpayer dollars by asking state and federal authorities to waste their time on such a silly matter of perfectly legal politics."

Poizner's request to Brown's office comes as the attorney general considers running for the Democratic nomination for governor. Polls indicate that Brown would beat Whitman or Poizner were November's general election held today.

Brown is widely expected to officially announce his candidacy in the coming weeks. Currently, he has an exploratory committee that allows him to raise large sums for a potential run.

Brown was California governor from 1975 to 1983. He may seek another two terms as governor because he led California before term limits were enacted.

From Legal Newsline: Reach staff reporter Chris Rizo at chrisrizo@legalnewsline.com.