Despite a go-ahead signal from Palestine Liberation Organization headquarters in Beirut, West Bank Arab leaders are planning to boycott an Israel-Palestine symposium scheduled to begin Saturday in Washington, Palestinian and Israeli sources said today.

Although 11 prominent West Bank leaders, including mayors of Arab towns and towns and other political leaders, accepted invitations to the conference, most of them have cancelled because they fear the symposium will turn into a forum to promote the Camp David peace accords.

Israeli backers of the conference, sponsored by the leftist New Outlook Middle East magazine, said if the Arab leaders do not change their minds and attend, the symposium will turn into "just another discussion between Israelis and Americans." They said, they still hold out hope the Arabs will attend the meeting.

Retired Gen. Mattiyahu Peled, a leading Israeli peace activist, said Rakah, the Palestinian Communist Party, and the "Sons of the Village" movement, a small but militant Israeli Arab group, have been exerting intense pressure on West Bank Arab leaders not to attend the conference.

"They keep hammering away at the idea that anyone who attends will be subjecting himself to persuasion to support the peace treaty and autonomy for the West Bank and Gaza Strip. They have been very effective," Peled said.

Peled said that Saturday he was given "a very impressive list" of 11 names of West Bank leaders who said they planned to attend. He declined to identify them, but source said they included the mayors of virtually all the West Bank towns. The mayors invited are outspoken supporters of the PLO and are opposed to the peace treaty.

Peled said, and Palestinian sources confirmed, that the PLO approved the West Bank mayors' attendance if they formed a "significant" and united delegation. The PLO is understood to have said if the West Bank leaders were divided, a delegation should not be sent.

Sources said that Gaza Mayor Rashid Shawa, who at first declined the New Outlook invitation and then accepted, was pivotal in the boycott when he again reversed himself last week and said he would not go to Washington.

"They were afraid to antagonize the Communist Party because they have been having some political difficulties. They were told that we are misleading them and trying to lure them into the policies of the Israeli government,' Peled said. The communists have supported the Palestinian cause in the past.

"All the ideas now being spread by special Ambassador Robert Strauss that there are Palestinians ready to join the autonomy talks in nonsense," Peled said. "The only way to counter that is to come to the conference and decide we all reject the substitutes that are being offered."

Ramallah author and Palestinian activist Ramonda Tawil called the boycott a "great tragedy," and said the West Bank mayors might change their minds if the U.S. State Department reversed its decision to refuse an entry visa to top PLO official Issam Sartawi, who also was invited by New Outlook. The U.S. policy has been to restrict travel by PLO officials to the United Nations in New York.

"If the Americans gave Dr. Sartawi a visa, it would be a great encouragement to the West Bank mayors to attend, Tawil said. Otherwis, great opportunity for a dialogue is being wasted."

Shawa, in a telephone interview, first said he was refusing to attend the conference "because I'm tired and they need younger men." But he added, "Also, it attending could be misinterpreted as cooperating with people whose basic opinion is the same as Israel's."

He said the symposium should be confined to "expressing the Palestinian position about independence and not debating Camp David."

Mohammed Milhem, mayor of Halhul, said "If Sartawi were going, it might be different. I personally wanted to attend, but I was not willing to attend as an individual. It should be part of a full, significant delegation, and I don't want to get involved under the umbrella of Camp David. The people in the occupied territories don't want to talk about alternatives to the PLO."