Israeli Foreign Minister Moshe Dayan said yesterday that even if the Palestine Liberation Organization changes its convenant to eliminate its pledge to destroy Israel that "would not be enough for us."

Dayan, interviewed on "Issues and Answers" (ABC, WJLA), thus reiterated the hard-line position of Israeli Prime Minister Menahem Begin that the PLO, which claims to be the sole representative of the 3 million Palestinians, can never change and as an organization, can never be dealt with by Israel.

But Dayan went further than he has in the past in voicing Israel's willingness to work with palestinians, including PLO members, in discussing substantive issues such as the future of the West bank of the Jordan River and the Gaza Strip at a Geneva conference on the Middle East.

In a separate interview broadcast on the same program, Egypt's foreign minister, Ismail Fahmi, seemed to appeal over the head of President Carter by saying that the "big silent majority" of Americans should be asked their views about the Arab-Israeli dispute.

Carter "should consult the masses in the United States, not only the Jewish lobby" in deciding policy on a peace settlement. Fahmi said. While it is not necessary for the Palestinians to take over Israel, "the Palestinians should have a right to go back to at least a part of their country," he said. "They must have their own national homeland exactly like Israel."

Dayan, as he has in the past, rejected the idea of a Palestinian homeland. He said President Carter "still thinks there should be a homeland or entity . . . something that has to do with Jordan."

The Israeli foreign minister said he saw no difference between a "homeland, entity or state." Earlier he said the issue of a separate Palestinian state will not be raised at the Geneva conference, which the United States wants to convene in December. But if it did come up, "we would walk out of the conference," Dayan said.

ABC interviewer Barbara Walters asked Dayan about a statement two weeks ago by PLO Chairman Yasser Arafat that if Israel accepted an independent homeland for the Palestinians, the LO would accept United Nations Security Council Resolution 242, which recognizes the right of Israel to exist.

Dayan noted that the PLO earlier this year reaffirmed its official charter, which calls for destroying Israel as a Jewish state and replacing it with a greater Palestine in which Arabs and Jews would have equal rights.

Asked whether Israel would accept the PLO if it changes its covenant. Dayan replied, "No, I think they have to change their guts." He said he thought "they have to change their planning and concepts to be not what they are. Just to change a piece of paper would not be enough for us."

He quoted Syrian President Hafez Assad as saying recently that for the Arabs, a Palestinian state would be the "first stage" and that the "next stage would be the destruction of Israel."

Dayan, however, showed considerable flexibility in discussing the mechanics for convening a new Geneva conference. An earlier conference, chaired by the United States and the Soviet Union, borke up in disarray after only two days of meetings in December, 1973.

Dayan confirmed what has been reported earlier about a U.S.-Israeli agreement on procedure at a new one - that an opening session would be attended by Israelis on one side and a united Arab delegation on the other; that bilateral groups - such as Israel and Egypt, Israel and Syria, Israel and Jordan - would then meet to consider separate peace treaties, and that Israel and multinational Arab groups would consider such issues as Arab and Jewish refugees.

Dayan also spelled out some additional elements. One was that Israel would meet with a mixed group of Egyptians, Jordanians and Palestinians to discuss the West Bank and the Gaza Strip on the Mediterranean north of Egypt. Another element was that PLO members would be acceptable to Israel so long as they do not say they represent the PLO.

"The point is not who the person is but who he represents," Dayan said. "If he says he represents the West Bank, it is okay. If he says I am here (and) though I am the mayor of hebron or Nablus . . . I am here representing the PLO, then it will not be okay."

Fahmi's comments were taped Friday and Dayan was questioned two hours before air time yesterday. Walters and Fahmi declined to appear on the same TV set with Dayan.