Key organizers of a 20th-anniversary civil rights "March on Washington" moved yesterday to shore up Jewish support for the event by stating they will avoid any specific statements about U.S. foreign policy and publicly disavow any anti-Semitic or anti-Israeli statements that might be made at the Aug. 27 gathering.

They also have promised to instruct parade marshals to screen all placards and banners to make sure they adhere to the general march theme of "Jobs, Peace and Freedom."

However, the march will proceed without the support of a number of major Jewish groups, as well as other key organizations including the National Urban League.

"We intend to highlight in our legislative and official policy statements the goal of peace. We will not articulate a specific strategy for achieving it," Coretta Scott King and D.C. Del. Walter E. Fauntroy said in a letter to Rabbi Alexander M. Schindler, president of the Union of American Hebrew Congregations.

But the assurances announced yesterday seemed only to fan the controversy that has sprung up around the march in recent weeks. And there were complaints by several groups who want the march to adopt specific foreign policy stands that Fauntroy and King are making concessions to Jewish groups that aren't expected to actively participate in the march anyway.

The historic 1963 march led by Dr. Martin Luther King Jr. championed the goals of jobs and freedom for all Americans. Organizers of the 20th-anniversary march have broadened that theme to include the goal of peace in the world, and therein lies the problem--for in trying to lay out specific peace concerns and foreign policy objectives, the question of U.S. involvement in the Middle East has been a major sticking point.

Several national Jewish groups, including the American Jewish Committee, the Jewish War Veterans and the Anti-Defamation League of B'nai B'rith, already have withdrawn their support for the march or refused to participate.

They complain march organizers have taken on controversial issues unrelated to civil rights, sanctioned an agenda critical of U.S. support for Israel and opened the march to a well known critic of Israel, former Sen. James Abourezk, who now lobbies for Arab causes.

The expanded march theme also has cost the participation of the National Urban League, one of the nation's largest black civil rights groups, which said this week that widening the focus of the march likely will limit its impact.

March coordinator Donna Brazile said yesterday, however, that 715 national groups have endorsed the march and plan to have contingents present. And she said she gets 20 calls a day from local Jewish groups which support the event. March organizers have said they expect to have at least as many, if not more, marchers as the 250,000 who joined the 1963 gathering.

Neither King, wife of the slain civil rights leader, nor Fauntroy could be reached yesterday to comment on the letter, which differs sharply from earlier pronouncements that the march would oppose U.S. policy in the Middle East as well as in Central America and South Africa.

March participants have been working for weeks on position papers intended to spell out specific goals in the areas of jobs, peace and freedom. The Middle East section of the foreign policy paper, in particular, has been drafted and redrafted several times--getting shorter and more vague with each revision--in an effort to reach a consensus.

Some of those involved in drafting the various position papers said yesterday that some organizers intentionally sought to expand the scope of the march but recognized that some Jewish and black groups would oppose going beyond the traditional civil rights goals of 20 years ago.

"This is a new day and the issues are more complex," said Jack O'Dell of Operation PUSH, whose leader, the Rev. Jesse Jackson, is one of the co-chairs of the march. O'Dell said there had to be a multi-issue coalition because all the issues are related.

O'Dell said "it's not news" that blacks and Jews have split over U.S. Middle East policy, particularly since several black leaders have visited with Palestine Liberation Organization officials in recent years.

And he and others, including march coordinator Brazile, complained yesterday that many Jewish groups withheld support for the expanded march from the beginning yet worked behind the scenes to pressure march leaders to tone down or eliminate any statements on the Middle East.

James Zogby, executive director of the American-Arab Anti-Discrimination Committee, said yesterday that his group didn't originate the Middle East statements but did help draft compromise language for the position paper.

"We didn't write the call--blacks wanted a Mideast position," Zogby said. "And it smacks of racism to say blacks shouldn't talk about foreign policy."

Zogby charged that key leaders of the march made concessions on the language and other march issues because some Jewish groups, specifically the Union of American Hebrew Congregations, threatened to pull out of the march, pressure labor groups to do the same and create bad publicity for the event in the media.

The UAHC declined to respond to Zogby's specific allegations yesterday. Rabbi David Saperstein, a codirector and counsel for the group's religious center, issued a statement saying the process of developing the position papers was "handled with integrity," resulted from an ongoing dialogue, and represented the coalition's viewpoints.

Schindler, whose group represents 760 reform synagogues, said in a separate statement that he was "gratified" and "heartened" by the assurances from King and Fauntroy. "In that spirit I have accepted the invitation . . . to deliver the closing benediction," said Schindler, who urged other Jews to participate in the march, which is being held on a Saturday, "in whatever way they deem appropriate to their observance of the Sabbath."

Hyman Bookbinder, Washington representative of the American Jewish Committee, said yesterday, however, the letter to Schindler "doesn't really meet our broad objections. The organizers made a serious mistake when they moved away from the 1963 civil rights goals into complicated foreign policy questions." He said he might march as an individual, but that his group wouldn't back march policy statements it views as "too pro-Third World and anti-American."

But O'Dell argued yesterday that the success of the march "at this point doesn't depend on any group that has not yet come on board . . . it's not a civil rights march, it's a march for jobs, peace and freedom, and that's who's marching."