THIS WAS HARDLY your usual Washington press corps briefing. For one thing, it was held over a four-course luncheon for 48 at the F Street Club. For another, it was presided over by Robin Chandler Duke, a socialite-activist whose interests have graduated from high fashion and decorating to Third World population problems and legalized abortion.

The whole thing, said one reporter, smacked of money and power. It was the kind of luncheon the anti-abortion forces could never have brought off in Washington. They don't have the connections. Everything was exquisitely orchestrated -- all the way from the invitations to the floral centerpieces, to the perfect asparagus and finger bowls on lace doilies. You knew straight off, from the moment Robin Chandler Duke stood up before dessert and tapped her goblet for attention, that she was rich. And connected. You knew it even before she started name-dropping.

Wednesday's lunch was definitely on the high chic side of the abortion controversy, but by the time the waiters and waitresses took away the dessert plates (fresh strawberries, vanilla ice cream and finger cookies) it had become obvious that a class act in the pro-choice forces had decided to play rough.

Robin Duke is president of the National Abortion Rights Action League (NARAL), which claims 88,000 members and which has concentrated since 1973 by lobbying Congress to preserve legalized abortions. That has not been terribly effective. "What's not coming through is . . . we are speaking for the mainstream," said Duke. Vulnerable members of Congress who are pro-choice in their hearts are afraid to vote that way because they will be targeted for defeat by anti-abortionists, she said.

NARAL's genteel approach to lobbying Congress has not worked. Congress has voted repeatedly to phohibit the use of federal funds for indigent women's abortions. It has been far more responsive to the anti-abortion forces that have deluged Congress with mail, targeted pro-choice members for defeat, staged huge rallies every year, and indulged in outrageous behavior such as labeling their opponents "baby killers" and invading abortion clinics. Now, NARAL is taking off the white gloves.

It is, said Duke, going "to identify politically active pro-choice citizens and alert them of the threat." She said, in effect, NARAL is going to borrow a few pages from the opposition. It already has given over $100,000 to pro-choice congressional candidates this year. It has hired nine state organizers to train pro-choice volunteers in effective campaign work. It has raised a $250,000 war chest to fight the anti-abortion forces who, to hear the NARAL people tell it, are poised on the right wing of the political spectrum ready to descend and destroy Life As We Know It.

Karen Mulhauser, NARAL's executive director, told the press that if more people understood what the anti-abortionists were up to, more people would be up in arms about it. Not only do they want to ban abortions, she said, but they also want to ban the use of some oral contraceptives and intrauterine devices that prevent fertilized eggs from attaching to the uterine wall. Spontaneous abortions would be suspect, she said. Women and doctors would face murder charges. The anti-abortionists are pushing hard in Congress and in state legislatures to secure passage of a constitutional amendment banning abortion except to prevent the death of pregnant women. If the anti-abortionists have their way, goes NARAL's new message, things won't be as bad as they were before the Supreme Court legalized the procedure in 1973. They'll be worse.

To prevent this, NARAL is mounting a campaign to help pro-choice legislators, to make themselves as powerful a force as the anti-abortionists have made themselves. NARAL is going to give campaign contributions, and it is going to swamp Congress with 1.5 million postcards saying "I'm pro-choice and I vote," and it is going to drum up volunteers for pro-choice candidates. It is going to be doing all the things a political movement under attack should have been doing all along.

It has not had the manpower to do it, and it's stayed ahead in the abortion fight only because the courts have been running interference for it against legislative efforts to limit access to abortions.

So NARAL is taking up accepted political strategy. But that's not all. The organization also has developed a series of radio spots about illegal abortions that Mulhauser played on a tape recorder while the waiters cleared the dessert plates and served demitasses of coffee. Here, things got a little bizarre.

The radio spots featured the voice of a male announcer who sounded as if he might have under-studied for "Reefer Madness." Women's voices described illegal abortions being performed on tables covered with old newspapers and in back alleys. One woman described the death of her own mother from an abortion. She said her mother's body rested in a casket in the family living room for three days. The speaker said her little sister crawled into it. The message in the radio spots is of coat hangers, knitting needles, infections and death.

Mulhauser said later that there was a lot of internal discussion within the organization about the media campaign and tone. A poll showed them that people who are strongly pro-choice are motivated by the fear that, "if abortion is illegal again, women are going to die." That led to the conclusion that, "once they get alarmed enough, they will want to get involved."

The ads are certainly alarming. They are also disturbing. In addition to having anti-abortionists hollering "baby killers" across the political scene, we are now faced with the prospect of having the pro-choice people abandoning their more reasonable ways in favor of alarmist "women killer" ads on the air waves.

"It's ironic," said Mulhauser, "that in order to get abortions out of politics, we have to get political." It's ironic, she said, and they may be going too far. Without giving the more accepted political campaign approaches a fair chance, NARAL has bought into the grim reaper hysteria of the anti-abortionists through their ads.

And hysteria is tough to take seriously, no matter how nicely it's served.