Undoubtedly the week's least lavish party for an Academy Award nominee was the one held last night in the lobby of the Biograph: wine and cheese for those who offered a $1 contribution.

No matter. People might feel like nibbling and sipping after the Washington premiere of the smoothly professional, socially aware and creatively nostalgic "With Babies and Banners," which tells of the 1936-37 sitdown strike at General Motors that put the United Auto Workers on the map.But even a cast-iron constitution would lose all appetite after the co-feature, "Nicaragua: September 1978," which deals graphically and powerfully with what the film calls Anastasio Somoza's "genocidal war against the Nicaraguan people."

"The picture will have its Los Angeles premiere on March 22," said Lyn Goldfarb, labor historian and co-producer of "With Babies and Banners."

"We're hoping that the timing will help us to win the Academy Award on April 9; at least, it will give a lot of people who will be voting a chance to see the picture."

The timing of the picture's first Washington run, which began the day after its nomination for an Oscar was announced, was a happy accident, according to Goldfarb. "I only learned about the nomination yesterday," she said. "I called my parents in California, and they told me they had just read about it in the paper."

The 46-minute film, produced by the D.C.-based Women's Labor History Film Project, has already been shown at the 1978 New York Film Festival, and has won prizes in Germany, Switzerland and France.

"It took 3 1/2 years to make," said director Lorraine Gray, "including 2 1/2 years that we spent doing research, finding old footage and still shots taken during the strike. We sent out literally hundreds of letters all over the United States and spent months combing the files of the National Archives.

"We found film in closets and in old, dusty boxes in the back rooms of union halls. Anne Bohlen (a co-producer) did most of the work on that, while Lyn concentrated on getting the oral history and I directed. It's the first film I have directed."

Shuttling deftly between past and present, the film blends the reminiscences of women at a 40th anniversary celebration of the strike (shot in color) with black-and-white footage that shows police using clubs and tear gas on strikers and chasing a woman picket, as well as the National Guard coming in with machine guns mounted on vehicles.

The film's focus is on the organization of the Women's Emergency Brigade, whose participation helped the sit-down strikers to hold out until General Motors caved in and added an important element to the organization and the propaganda effort of the strike.

One woman in the picture recalls how they tried to put her to work in the strike kitchen and she insisted on marching in the picket lines: "We made up our minds that we were going to be as big a part of it as the men, and we were."

"With Babies and Banners" has a happy ending implicit throughout the film, but "Nicaragua: September 1978" shows no sign of an end in sight. People interviewed in the film include a Catholic bishop who says that armed resistance is legitimate when all other means of seeking justice have failed, a priest who says that the National Guard arrested him on charges that he had guerrilla arms "hidden in the basement of my church -- but the church has no basement" and an economist who analyzes the social and political conditions that have led to armed revolt in Nicaragua.

But the most telling scenes are those of destruction and mourning: a mother on the verge of hysteria describing how small children were taken from their homes and shot; a picture of a bullet-riddled Red Cross ambulance; the charred body of a Red Cross worker lying in a street.

"The taxes you have been paying are being used to kill the Nicaraguan people," Magda Levin, a Nicaraguan exile who is organizing an American branch of AMPRONAC (The Federation of Nicaraguan Women) told the Biograph audience. She called for an American boycott of all Nicaraguan products, particularly meat, for which almost all the profits go to Somoza, and she asked the United States to intervene to prevent the sale of arms to Somoza by U.S. allies such as Guatemala and Israel.