Congressional candidate John Flannery stood beside Ethel Kennedy in her living room at a Hickory Hill fund-raiser. Against a backdrop of antique tables crowded with silver-framed photographs of fallen Kennedys, he ran his fingers through his mop of red-blond hair and began to speak:

"I accepted a challenge that day," he said of the time in high school that he heard a speech by then-senator John F. Kennedy.

And later: "Ethel told someone I could pass for a member of the family."

It wasn't the first attempt by a fledgling politician to cloak himself in the Kennedy mantle, but it certainly was unabashed, and just the kind of brash performance the ambitious, 38-year-old newcomer has displayed throughout his uphill fight to unseat two-term incumbent Republican Rep. Frank R. Wolf in Northern Virginia.

"John is an extremely charismatic personality who does tend to get people -- people react to him," says wife Bettina Gregory, an ABC television correspondent who has taken time off to manage her husband's campaign. "He's a real fighter, and not the average schleppy politician you're going to meet."

The Bronx-born Flannery, a former federal prosecutor who moved to Arlington from New York two years ago, has charged into the largely affluent, largely suburban 10th district like a cocky city kid determined to show the new neighborhood a thing or two.

"I'm running for Congress, not highway commissioner," he says, referring to what he views as Wolf's myopic attention to local issues like commuter restrictions on I-66 and jet traffic at National and Washington Dulles airports. "There are issues in this district that cry out for national leadership," he says.

His campaign brochures are illustrated with a pencil portrait that resembles Robert F. Kennedy and his speeches are studded with references to the the New Frontier. His attacks on his opponent, however, are all his own.

The Flannery offensive also has become a central issue in the race, with Republican officials and others charging that Flannery has distorted Wolf's record as well as some of his own accomplishments.

Others, Republicans as well as a few Democrats, look askance at Flannery's campaign which they say is not so much his promised "shared coalition of pain and dreams," as a combination of ambition and elbows, one that exacerbates the image of a carpetbagger on his way to better things.

Flannery heatedly denounces the criticisms as the work of Republican partisans nervous at his progress. "These attacks are coming only because we've got something going here," he says. "We're on the move, and these guys can't stop us."

Early in the campaign, Flannery had to apologize for falsely stating in his campaign brochures that Wolf had said a nuclear war was winnable. He further infuriated Wolf supporters by adding that even if Wolf hadn't said it, "he acts as if he believes it."

"Absolutely not true," says Wolf spokesman Jim Boyle. "Frank has consistently said and written that a nuclear war could never be won. This kind of thing is part of a pattern. Flannery gets things in his own mind and convinces himself they're true. It's one thing to disagree on the issues, but it's another thing to misrepresent your opponent's views."

Nothing has raised hackles more than Flannery's description in campaign brochures of his successful 1976 prosecution of a drug dealer named Antonio Flores: "John . . . put in jail, among other dangerous drug dealers, the sole buyer of $65 million worth of pure heroin in the so-called French Connection case."

Local Republicans, as well as federal prosecutors in New York say that calling the Flores case part of the "so-called French Connection case" is misleading.

"The thing that just galls me is that everybody knows the French Connection case," says Brian P. Gettings, a Republican lawyer in Arlington and former federal prosecutor. "He had absolutely nothing to do with it, but by this statement he clearly attempts to get the thought across that he was the big cheese in this thing. And that's wrong."

Flannery says he is using the phrase "the so-called French Connection case" as a generic term and that his usage is correct. "The French Connection was more than an hour and a half movie," he says. "It wasn't just one case, it was hundreds of cases, a pipeline of drugs from France into this country."

John Cooney, former chief of the New York narcotics division while Flannery was there, says that Flannery's explanation is stretching it. William Tendy, current deputy U.S. attorney in Manhattan and chief of that office's narcotics' unit from 1957 to 1970, agrees. "The French Connection case was made in 1962," he says. "There is absolutely no relation between that case and the Flores case."

Flannery's style has irritated some in the district. Remarks like "too often people have run for office here like they were running for student council," have not gone unnoticed. "If he loses, he won't have a friend in this district," says one activist who asked not to be named.

In New York, where he prosecuted drug and corruption cases as an assistant prosecutor in the prestigious U.S. attorney's office, and on Capitol Hill, where he wrote two well-received reports about fugitive financier Robert Vesco and the FBI's investigation of Labor Secretary Raymond Donovan, Flannery got high marks for results but mixed ones for comportment, according to numerous acquaintances.

"He's very talented, but he's the most ambitious human being I've ever seen," says Jim Phillips, a Capitol Hill staffer with whom Flannery tangled. "He was very difficult to work with because he wanted everything his way, and he wanted to get full credit for team efforts."

Phillips and others say that Flannery has exaggerated his role as a Senate investigator. "He makes himself out to be a surrogate senator, and that's just not the case."

Flannery's supporters say the criticisms should be attributed to envy and political backbiting rather than flaws in Flannery's character.

"He had some friends and some enemies," says one former boss. "He's never been a bashful guy, and he's very pugnacious, very feisty, sort of a street guy in some ways."

"If you're going to accomplish anything in this world, not everyone is going to love you," Flannery says.

Democrats say they believe the Flannery campaign is holding its own, though neither party has released any polling results and Republicans say Wolf is ahead by a comfortable margin.

"There's no question about it. When he Flannery first began, I thought he was going to get blown away," says Arlington County board member Al Eisenberg. "Now I think he has a good fighting chance."

It's a fighting chance in a fickle district. About one-fifth of the 10th's 325,073 registered voters are new to the district every year, and for the past decade the district has chosen its congressmen from both parties, usually by narrow margins.

The 10th district includes Arlington, Falls Church and the city of Fairfax as well as the burgeoning suburbs of northern Fairfax and Loudoun counties, It is, by and large, an affluent, well-educated district, with an unemployment rate that hovers at a relatively painless two percent.

Nearly half of the district's voters either work for the federal government or live with someone who does, according to local political consultants. Wolf has made their care his cause, but Flannery says Republican Wolf can't represent federal workers when his president has been attacking them. Voting for budgets that produce federal layoffs, as Wolf has, and then sponsoring local job fairs, Flannery says, "is like emptying an ocean with a teacup. He can't have it both ways."

Wolf, a softspoken, poker-faced father of five is a former Capitol Hill lobbyist and Interior Department aide who has lived in Northern Virginia for 23 years. He lost his first two bids for Congress, but came back to win the third in 1980.

Flannery moved to Virginia after marrying Gregory. The two met in Washington during the air traffic controllers' strike; Flannery was representing the airline industry and Gregory covered the story for ABC News. It is the third marriage for both.

Together Gregory and Flannery have lured liberal luminaries such as Ethel Kennedy, House Speaker Thomas P. (Tip) O'Neill and Pamela Harriman to their cause as well as courting the rank and file. "Bettina can charm the apples off the trees," says Democratic activist Marie Ridder.

They have also attended numerous Democratic dinners to buttonhole politicians, and he has loaned his campaign more than $70,000 of his own money. Unemployed for the past year, he says he is living off of investment income.

The political contest of plain versus fancy has produced some odd moments. Flannery's repeated references to his own South Bronx roots, for example, have prompted Wolf to remind voters of his roots in South Philadelphia. The result is the unusual spectacle of two candidates for office in one of the most comfortable districts in the nation competing over whose boyhood collar was bluest.

Although he has had a lifelong interest in politics, Flannery says he came to Washington "because I fell in love with a woman. Then I looked around and saw there was no protest to what I saw Wolf doing . . . I thought we deserved better and I really didn't see anyone doing it."

Flannery has won the endorsement of nuclear freeze groups, several labor unions and the Virginia teachers. He opposes the Reagan budget cuts and has criticized Wolf for failing to support the Equal Rights Amendment.

To those who say that he is too new to represent the 10th, Flannery snaps: "You don't have to live in a district 10 years to know how to represent it. My wife is here, I have property here and I expect to live here the rest of my life. I'm going to put this district on the map."