CALIFORNIA ELECTIONS / U.S. SENATE : Dueling Attack Ads Unleashed by Candidates : Feinstein and Huffington hit the airwaves again with a new series of negative television spots. Both sides appear to take some liberties with the facts.

In their record-setting and vitriolic race for the U.S. Senate, Democratic incumbent Dianne Feinstein and GOP Rep. Mike Huffington continue to burn up television time with a series of ads that paint each other as frauds, tax cheats, even lawbreakers.

The ads represent the latest salvos in what is now--at more than $27 million--the most expensive congressional race in U.S. history. And with three weeks left in the contest, it is likely that millions of dollars more will be spent by the pair to reach California voters the fastest way they can--over the airwaves.

Feinstein’s latest commercials, including one released Tuesday, portray her challenger as a do-nothing freshman congressman whose previous business career was riddled with scandal. Huffington, her ads conclude, is a “Texas oil millionaire Californians just can’t trust.”

Huffington’s latest ad describes Feinstein as a multimillionaire and political waffler. She is, says the ad: “A career politician who will say or do anything to stay in office.”

The ads, like two dozen before them in this contentious race, contain elements of truth but also take liberties, some significant, with the facts.

For example, NBC News Tuesday demanded that the Huffington campaign immediately halt a commercial that claimed the network was critical of the Feinstein campaign. In that ad, which stopped airing Monday, Huffington’s campaign claimed that “NBC News labeled (a Feinstein) ad the ‘meanest, sneakiest’ of the year.”

NBC attorney Roberta R. Brackman said the ad was false.

Huffington spokeswoman Jennifer Grossman defended the ad by arguing that in 1988 NBC had been critical of an ad by then-Senate candidate Leo McCarthy that was similar to an ad used by Feinstein in her 1990 race against Wilson. So even if NBC had not directly criticized Feinstein, Grossman said, “Plagiarism is not going to excuse Dianne Feinstein.”

Here are some of the other claims and analysis:

Huffington ad: “Which candidate is worth $50 million, but uses a taxpa y er - paid chauffeur to get to work? Feinstein.”

Analysis: The latest Huffington commercial, which began airing statewide Sunday night, highlights Feinstein’s well-documented wealth. The Roll Call newspaper in Washington has estimated her net worth at about $50 million, primarily because of the assets of her husband, investor Richard Blum. (Huffington’s worth has been estimated at $75 million.)

And although she is driven to and from work, Feinstein has denied that taxpayers are footing the bill. Earlier this year, she told The Times that no taxpayer money was spent on personal driving services for her, though a staff member does drive her to business appointments during the day.

Huffington ad: “Which one double-dips, taking a $133,000 Senate salary and a $33,000 San Francisco pension? Feinstein.”

Analysis: As a former San Francisco official, Feinstein is entitled to the pension as well as her salary as a senator. Feinstein campaign manager Kam Kuwata on Tuesday sought to turn the issue against Huffington. “She has worked in her life, unlike Congressman Huffington, who has only taken money from his father,” Kuwata said.

As for the amount, Kuwata countered that the senator donates about $200,000 a year to charities--a total that exceeds both the salary and pension.

Huffington ad: “Which one broke the law so massively she got the biggest statewide candidate fine in California history? Feinstein.”

Analysis: Feinstein did pay a $190,000 fine for violations of campaign reporting laws in connection with her 1990 campaign for governor. The amount remains a record fine for a statewide candidate in California. Kuwata points out that both Feinstein and Gov. Pete Wilson paid large fines to the state Fair Political Practices Commission because their errors--blamed on accounting mistakes--occurred during expensive campaigns.

The ad’s “broke the law” wording might suggest criminal law violations, when in fact Feinstein’s campaign violated civil campaign reporting laws.

The Huffington ad also attacks Feinstein on two other points: saying that she has opposed term limits and that she voted herself a pay raise in the Senate. Both are true.

Feinstein’s camp, meanwhile, has leveled its own barrage of accusations against Huffington in two current commercials.

Feinstein ad: “Associated Press reports that government records describe Huffington as secretive, threatening and greedy.”

Analysis: The ad, which began airing early this month, cites press stories critical of Huffington, including one by the Associated Press. But the points drawn from that story emerged from a civil lawsuit in Texas, not government reports or documents as the ad implies. Further, as Huffington’s campaign has pointed out, the accusation was leveled in a countersuit filed by an oil company being sued by a Huffington company. In the countersuit, according to the AP story, the company charged that the Huffington family lawsuit was prompted by “avarice and greed.”

Feinstein ad: “He claims he’s for cutting government spending, but the ‘Hypocrisy Index’ of the National Taxpayers Union lists Huffington because he promised to vote for big spending cuts, but voted for huge spending increases instead.”

Analysis: The newest Feinstein ad, which began airing Tuesday, says that Huffington’s congressional record has been criticized by the Washington-based National Taxpayers Union. And the group does list Huffington as among 31 federal lawmakers to have voted for large federal outlays after promising big cuts in spending.

But Huffington’s spokeswoman Grossman questioned the validity of the NTU’s method for ranking members of Congress. Previously, she said, the organization counted all the legislation sponsored by a lawmaker--an approach that Huffington’s campaign has said put Feinstein high on the list of spenders.

Now, it just counts the votes of legislators--an approach, Grossman said, that hurts freshman legislators whose bills often never see the light of day.

But Feinstein’s campaign manager countered that Huffington’s camp is guilty of a different kind of hypocrisy if it is now disputing a taxpayers’ group it once embraced in its own ads.

“Either you use their numbers or not,” Kuwata said. “You can’t have it both ways.”