A National Council of Churches study of the conflicts in the Middle East has threatened the most serious breach in decades in relations between mainline Protestanism and the American Jewish Community.

In an unusual show of unity, 17 of the nation's most powerful religious and communal Jewish organizations are refusing to appear before a special panel of Protestant churchmen studying Israeli-Palestinian conflict.

The hearings, to be followed by a three-week fact-finding tour of the Middle East, are aimed at helping the NCC develop a new and comprehensive policy statement on the Middle East Conflict.

Jewish leaders, many with decades of interfaith dialogue behind them object to the idea of the formal, congressional-style hearings, and to the Ncc formulation of the issues they were asked to address, calling them "slanderous" against Israel.

'the [NCC statement of] 'issues for consideration' attempts to place Israel on trial, and we judge them to be prejudicial and tendentious," said a joint statement signed by leaders of 14 the Jewish groups.

Part of the difficulty appears to be a culture gap between Jewish and Protestant styles of doing business. Many Protestants denominational meetings regularly schedule hearings both to develop information and to afford everyone an opportunity to speak.

But that process "is unfamiliar to us," said Rabbi Dan Polish of the Washington office of the Synagogue Council of America.

"Many of the groups were ones the NCC has had longtime relations with," Polish observes. "Now they turn around and treat us as defendants in a dock."

Polish and other Jewish leaders indicated that the wording of the issues for discussion was even more of a problem than the hearing process.

"The way the questions were worded, it became clear to us that only skewed conclusions [in favor of the Palestinians] could result," he said. "It all seems to portend for us the opposite of a dispassionate, open inquiry."

Ever since the 1967 war in Israel, the NCC has followed what it describes as an "even-handed" policy on the Middle East.But that policy has been denounced by Jewish groups as pro-Arab, and by member churches with strong ethnic or missionary ties in the Arab world as pro-Israel.