(CNN) - A new poll suggests the California battles for governor and the Senate remain quite close.
A Public Policy Institute of California survey released late Wednesday indicates that Democratic nominee Jerry Brown leads Meg Whitman, the Republican nominee 37 to 34 percent, with a large 23 percent undecided. Brown's advantage is within the poll's sampling error.
Brown is the state's attorney general and a former two-term governor in the 1970's and 1980's. He has also served as Oakland mayor and California secretary of state. Whitman, the billionaire former eBay CEO who also was an adviser and surrogate for Sen. John McCain's 2008 presidential bid, has spent more than $100 million of her own money so far on her bid for governor.
Brown led Whitman by one point in a Field Poll released earlier this month and by six points in a Reuters/Ipsos survey from June.
The winner in November will succeed Republican Gov. Arnold Schwarzenegger, who can't seek re-election because of term limits. Schwarzenegger has struggled to fix the Golden state's economy and has battled with state lawmakers over how to reduce California's massive budget deficit. The PPI poll indicates that only one in four Californians approve of the job Schwarzenegger's doing as governor.
In the fight for the Senate, the survey indicates that Sen. Barbara Boxer leads Republican challenger Carly Fiorina 39 to 34 percent, with more than one in five undecided.
Boxer, who is bidding for a fourth term in the Senate, led Fiorina by three points in the Field poll and by 4 points in the Reuters/Ipsos survey. Fiorina, the former Hewlett Packard CEO, who was also an economic adviser and surrogate for Sen. John McCain's White House bid, beat out two other rivals in the GOP primary in June.
The Public Policy Institute of California poll was conducted July 6-20, with 1,321 likely Golden State voters questioned by telephone. The survey's overall sampling error is plus or minus 2.7 percentage points.
–Follow Paul Steinhauser on Twitter: @psteinhausercnn