To hear Forbes magazine tell it, consumer advocate Ralph Nader is an "untrustworthy" figure who presides over a secretive "autocracy" of interlocking left-wing groups, fervently carrying water for the greedy plaintiff's lawyers who bankroll his causes.

In a cover story titled "Saint Ralph and His Web of Interests," the magazine last week performed what it called "a Nader-type raid on Nader," even questioning his claim that he takes home $15,000 a year and suggesting that he lives in a $1.5 million town house on Bancroft Place.

Nader, armed as usual with a thick sheaf of documents, denounced the magazine amid the clutter of his P Street NW office, calling the piece "malicious" and "amateurish." He said the editors were attacking him to ingratiate themselves with his longtime adversary, the insurance industry, and that Forbes's insurance advertising had jumped from an average of $199,000 to $259,000 per issue since a similar broadside last fall.

"I'm an old hand at receiving brickbats," says Nader, 56. "I've been raked over by the worst of the worst. But this is so incredible you fluctuate between outrage and laughter."

Forbes Editor James W. Michaels took Nader's counterpunching in stride. "Essentially the story grew out of a story we did last year on the whole tort situation," he says by phone from his New York office. "In the course of reporting, we discovered this very interesting nexus between Nader and his groups and the trial lawyers. ... If that's ideological, I'll eat my hat. It's just following a news story where it leads."

Michaels dismisses the notion that the magazine is courting insurance companies, saying that advertising revenue was up across the board and that insurance ads amounted to just 7 percent of the total.

In one sense the dispute is a cultural clash between two titans -- Nader the rumpled, perpetually outraged advocate railing at the establishment, and Forbes the self-described "capitalist tool" of the late Malcolm Forbes, constantly setting out to slay financial dragons.

The Nader story's heavy-handed tone has caused some grousing among more than a few staffers at Forbes's Manhattan office. Others detect a whiff of ideological bias in the fact that one of the authors, British-born journalist Peter Brimelow, is a former special counsel to Sen. Orrin G. Hatch (R-Utah).

"I am a conservative, or at least more conservative than most journalists," Brimelow says matter-of-factly.

Brimelow and co-author Leslie Spencer take a dark, almost conspiratorial view of Nader's public-interest lobbying. There is a two-page, five-color chart that purports to show connections between the Center for Study of Responsive Law, Public Citizen, Citizens for Tax Justice, Center for Science in the Public Interest and other organizations. Nader is said to exercise varying degrees of control over 29 organizations with combined revenues of $75 million to $80 million.

Former Nader's Raiders are "strategically placed in the elite media" and infiltrated the Carter administration, where they "shoveled" money to Nader groups, the article warns. Current Naderites pursue their "leftist ideology" with such fervor that some door-to-door fund-raising involves "song-singing boosterism redolent of a kamikaze sweatshop."

Nader says he's had little connection with most of the groups since founding them years ago. "They make it like it's a plot," he says. "These are groups of kindred souls. The whole idea of building a movement is to have them stand on their own two feet."

What really seems to exercise the Forbes authors is Nader's audacity in championing the right of plaintiffs to sue corporations for big damages -- suits that also happen to generate huge fees for lawyers. Nader stunned the business world in 1988 when he sponsored a California insurance reform initiative, Proposition 103, that beat four competing proposals despite a $70 million campaign by the insurance industry.

Four months before publishing a highly critical piece on Nader and the plaintiffs' lawyers last fall, Forbes ran a full-page house ad saying: "Clearly there has never been a time when it has been more critical for the insurance industry to tell its story. ... Be part of that story. Advertise your company's services in 'Insurers Outnumbered' appearing in the Oct. 16, 1989 issue of Forbes."

Since then, the crusading magazine has patted itself on the back for having "blown the lid on the obscene profits earned by contingency fee lawyers."

In last week's piece, the authors charged that Nader is "intimately entwined with a group of rich lawyers: the plaintiffs' bar," which they say pours big money into many of his groups.

"We're not saying that Nader's views are 'determined' by his financing," the article says. "We're being more charitable about him than he is about his own opponents. Nader's views could well just coincide with his backers'."

Nader readily concedes he has "made an alliance" with the plaintiffs' lawyers, but says most of the groups he founded get "less than 1 percent" of their revenues from such attorneys. "I wish it was 10 percent," he says. Two exceptions are Trial Lawyers for Public Justice Foundation, which Nader encouraged the lawyers to create, and the National Insurance Consumer Organization, which he says gets a third of its money from trial lawyers.

The Forbes assault turns personal by openly scoffing at Nader's claim that he lives on $15,000 a year, saying he rakes in up to $1 million a year in speaking fees and quoting an anonymous source as saying that Nader often travels by limousine and stays in luxury hotels.

Moreover, the piece attempts to debunk Nader's claim that he lives in "a simple room" near the office, saying that for nearly 20 years he has lived in a palatial-looking town house owned by his sister. Forbes helpfully published a photo of the place with the caption, "Wages of Virtue?"

An indignant Nader puts his speaking fees at $300,000 a year, but says he donates all but $15,000 to various research groups and charities. "I don't own a car. I work all the time. So what have you got? Rent, food, clothing, movies. I don't make a big deal out of this, the press does. I'm not hurting. I don't feel squeezed."

The consumer crusader says he only visits his sister's town house (and that it's worth a mere $600,000). "I'm not going to tell anyone where I live," he snaps. "Just the lemon owners alone drive you crazy. I've got to have a little privacy."

To Brimelow, however, such topics are fair game. "I don't think it's a personal piece, actually," he says. "The Saint Ralph thing is essential to his public persona, that he's beyond criticism. He's made this frugality in living a major part of his public persona."

As for Nader's charge that Forbes is "an insurance industry house organ," Brimelow says: "There's too much motive-mongering here. I don't say he's bought by these people, just that he's allied with them."

"Which is a doubt he won't give us," Michaels adds. "He's saying we're doing it for the most mercenary of motives."

Right up to the magazine's deadline time, the adversaries warily circled each other across the public policy canvas. Nader refused to grant the Forbes reporters an interview; instead they engaged in a feverish exchange of faxes and counter-faxes.

"I figure an interview is much more easily distorted," Nader says. "They can say, 'He said this, he said that, he smirked.' "