The delegate assembly of the Jewish Community Council voted 98 to 70 Thursday night to refuse membership to a new Jewish organization that differs from most American Jewish groups on some questions of relations between Israel and Palestinians.

The action of the delegate body overturned the 22 to 5 recommendation of the JCC's executive board last month to admit the New Jewish Agenda to membership in the umbrella organization of the Washington area Jewish community.

The New Jewish Agenda is a Jewish social action organization, with an 18-point platform dealing with economic justice, racism, anti-Semitism, feminism and advocacy of a nuclear freeze.

The opposition to its membership in the JCC, however, centered around the New Jewish Agenda's position on Israel.

"We say peace has to be made by negotiation between all parties concerned, including legitimate representatives of the Palestinians, not excluding the Palestinian Liberation Organization, on the basis of mutual recognition," said Deborah Goldman, a member of the local chapter and co-convener of the New Jewish Agenda's national Middle East task force.

Even more of a sticking point is the New Jewish Agenda's assertion of "the right of the Palestinians to national self-determination, including, if they so choose, the right to a state existing at peace with Israel," Goldman said.

The idea of a Palestinian state within the present boundaries of Israel is anathema to groups such as the Zionist Organization of America.

Irwin Stein, president of the local chapter of the ZOA, which mobilized much of the opposition to the New Jewish Agenda, said, "We feel a group like this is not within the mainstream of thinking of the Jewish community . . . They don't fall within the kind of thinking that is current in the Jewish community."

Charging that the New Jewish Agenda is "pro-Arab rather than pro-Israel," Stein said the group is "so far out we feel they really don't deserve membership ."

Goldman denied the pro-Arab charge. "We are first and foremost lovers and supporters of Israel," she said. "We contribute to and support our brothers and sisters there and their right to exist within secure borders."

Within the Jewish community some deplored Thursday night's vote as establishing a political loyalty test for membership in the council.

"To me, the JCC is supposed to be a broad umbrella organization, with all of us putting our ideas into it," said Phyllis Frank, past president of the council, who argued for admission of the New Jewish Agenda. "We don't agree on anything, ever," she said in praise of the pluralism of the Jewish community.

Moe Rodenstein, co-chair of the local chapter of the New Jewish Agenda, said the group sought to join the other 260 religious, educational, fraternal and social service organizations in the Jewish Community Council because "we'd kind of like to be a part of the debate . . . to say 'we are Jews; we're proud of what we're doing.' "

Also, he said, "it's important for us to work with a wide variety of issues . . . to try to push the Jewish community to concern with other issues than Israel and anti-Semitism."