Two small and privately sponsored conferences to promote dialogue on the Middle East are planned here this month between a "moderate" PLO leader and American and Israeli Jews. The sessions have provoked a call for a boycott by national Jewish leaders.

Under fire are a conference beginning tonight on "The New Imperative for Israeli-Palestinian Peace," sponsored by the American Friends Service Committee, and a conference on "American Jewish Responsibilities for Peace in the Middle East."

The latter is the first national membership meeting ever held by Breira, a small organization of American Jews committed to Israel's continued existence but also to more open debate on Israeli affairs among American Jews.

Both conferences will be held in the 4-H Center in Chevy Chase.

But on Wednesday, the State Department notified the Quakers that a visa would not be granted one of their major attractions, Sabri Jiryis, the PLO representative, to enter the country.

"Every call that we had from the State Department up through the end of last week was assuring to us that the visa would be granted," said Ron Young, Quaker agency official in Jhiladelphia who is one of the conference planners.

Young believes the American Jewish establishment pressured the State Department to turn down Jiryis' visa.

Arnold Forster of the Anti-Defamation League in New York admitted that his organization had urged the State Department to keep Jiryis out.

"The PLO's presence in Washington as an official organization, if permitted by the present administration, would be a signal to the world that there is a change in our foreign policy with respect to the PLO," Forester said.

"We brought this to the attention of the government and they agreed," he added. "We don't think a terrorist organization should be operating in the United States."

The State Department said that Jiryis' visa application was turned down because his lecture here was viewed as political activity and that it would be in conflict with American policy.

Israeli Ambassador Sincha Dinitz had urged on Monday that visas not be given PLO spokesmen.

In addition, Rabbi Max Ticktin, director of field services and leadership training for B'nai B'rith Hillel Foundation and officer of Breira, also withdrew from the Quaker meeting because of what he described as "pressures."

"We're approached at least two dozen prominent rabbis of leading synagogues or national organizations" in an unsuccessful effort to find a replacement for Rabbi Ticktin, Young said.

For the past six weeks, the local English-language Jewish newspaper, cisms of the forthcoming conferences, their sponsoring organizations and of any Jew who would be associated with them.

Late last month the National Jewish Community Relations Advisory Council, meeting in Miami, "strongly urged" that American Jews boycott both gatherings. A statement from the council's Israel task force stressed that "the organized Jewish community is absolutely opposed of participation in discussions of any type with PLO representatives."

Subsequently, the executive committee of the Jewish Community Council of Greater Washington met and reportedly by a 2-to-1 majority, adopted and expanded the position of the national organization.

Samuel H. (Buddy) Sislen, assistant director of the local council, acknowledged that no representative of either Breira or the Friends had been invited to the executive committee meeting.

The council's statement contended, among other things, that Breira was "utilizing its forthcoming conference to spark a major political initiative on behalf of the PLO cause with an eye to affecting U.S. policy to the Middle East via Congress, the media and the new administration."

The statement was sent to the 180 synagogues and other Jewish organizations that belong to the council, calling on them "to advise and caution their members about Breira's activities, which are injurious to Israel." The Quaker conference also was condemned in the statement.

Breira spokesmen deny the characterization drawn by the Council. "There is absolutely no question whatsoever but that Breira stands for the continued existence of Israel," said Dan Gillon, assoicate director of Breira, from its New York office.

Rabbi Ticktin described it as an organization largely of "young people who are pro-Israel but who are distressed by the limits on debate (about the Middle East) in the United States."

Gillon, an Israeli citizen, sees the debate over Israel in the Jewish community in this country becoming more limited.

"Just within the past couple of weeks, I've had four speaking engagements, in the New York area canceled," he reported. Breira-sponsored meetings are increasingly disrupted "by people determined to break them up. They don't question, they don't argue, they just shout slogans," he said.

Antagonisms within the Jewish community over the issue of Israel were heightened by a private meeting here last Nov. 15 among Jiryis and another PLO member and five Washington area Jews.

The meeting, and a similar one in New York City, was arranged by the American Friends Service Committee. The pacifist organization long has had a program, begun at the height of the U.S.-Soviet cold war tensions, of arranging such unofficial and private contacts.

Involved in the November conference here were Herman Edelsberg, former director of B'ni B'rith International; David Gorin, Washington director of the American Jewish Congress; Olya Margolin, representative of the National Council of Jewish Women; activist Arthur Waskow, and Rabbi Ticktin. All participated as individuals, not as representatives of their organizations.

Word of what was supposed to be the private conversation between the five American Jews and the PLO representatives leaked out.

The Conference of Presidents of Major American Jewish Organizations - one of the most representative Jewish bodies in the country - formerly condemned the secret meeting, stating the Jewish leadership group "vigorously opposes and deplores any meetings - official or unofficial - with the PLO."

"We were not negotiating" with the PLO, Rabbi Ticktin said. "We were trying to help in loosening the climate that would aid in the posture of the Israeli government . . . We were trying to find ways of loosening the log jam."

Rabbi Stanley Rabinowitz, of Adas Israel and president of the national organization of Conservative rabbis, charged that "both of these organizations, (the Friends and Breira) knowingly of unknowingly are fronting for the PLO."