Two candidates for the Ward 3 D.C. City Council seat unloaded a little incendiary rhetoric at a forum last night in a "me-too" bid to garner attention in a crowded race that was beginning to look like a square-off between candidates Mark Plotkin and Ruth Dixon.

Speaking before a gathering of about 100 people at the Foxhall Citizens Association candidates' forum, Democrat Jim Nathanson drew applause when he appeared to disparage Plotkin's brief career as a D.C. teacher, and Republican Gloria Corn brought gasps when she called Mayor Marion Barry a liar.

Hanging back stylistically, Democrat Mary Draper Janney averred that the best way to make progress in many areas of public policy is to negotiate and seek compromise.

Meanwhile, Jody Pappalardo, a Democrat who is a member of a slate formed by Dennis Sobin, a sex entrepreneur and candidate for mayor, also attacked Barry and surprised listeners when she ended her five-minute opening presentation after less than a minute, remarking, "I have lost my whole train of thought."

Previous forums have been dominated by Plotkin's attacks on Democrat Dixon, who was the leading challenger to retiring Council member Polly Shackleton (D-Ward 3) in the 1982 election. As Plotkin has done several times before in a campaign marked by vigorous debate on development in the ward, he called on Dixon and the other candidates to return campaign contributions received from real estate interests.

Nathanson, a public school teacher and ward party leader whom Shackleton has endorsed, turned to Plotkin during his opening remarks and asked him how long he had been a teacher. "Was that for one year, Mark, or two?" Plotkin, who later said he had taught for two years, has made strong statements in support of public education, as have other candidates.

Nathanson also recalled his role on the Ward 3 Citizens Advisory Council, noting that Dixon had been "strangely silent" during her tenure with the group; that Plotkin had not been a member but had offered a failed resolution for consideration, and that Janney had attended some meetings and taken notes.

"No more Mr. Nice Guy," said Plotkin as Nathanson took his seat.

Corn, distancing herself from the others by the vehemence of her opposition to the mayor, recounted what she said was a broken "promise" from Barry to provide drug-counseling funds to an organization headed by her.

"He is a liar," she said to mixed applause and hissing, "and I believe he is a thief."