The Israeli government decided today to allow two nationalist West Bank mayors, summarily expelled five months ago, to return to the occupied territory to plead their case before an Israeli Army appeals board.

The mayors, Fahd Kawasme of Hebron and Mohammed Milhem of Halhul, were expelled to Lebanon on May 3 several hours after six Israeli settlers were murdered in the overwhelmingly Arab town of Hebron as they returned from Sabbath religious services. The mayors later protested to the Israeli Supreme Court that they had not been given the opportunity to appeal their expulsion as Israeli legal procedure stipulates.

The Supreme Court, while expressing regret that the mayors were expelled before they had a chance to appear before the appeals board of the military government, rejected their request that the court order the military government to allow them to appear in person before the court. The Supreme Court suggested, however, that the review board should make the final decision.

The military board was scheduled to hear the case in Ramallah in the West Bank on Wednesday this week. It was generally expected here that it would reject the request. However, at a high-level meeting this afternoon presided over by Prime Minister Menachem Begin in his capacity as minister of defense, it was decided to allow the mayors to be present when their appeal is heard.

The board, made up of military officers, is sovereign in its decision. But it is thought unlikely that it will reverse the informal decision taken today on the highest level. Apart from Begin, the meeting was attended by he attorney general, Yitzhak Zamir; the military governor of the West Bank, Brig. Gen. Benjamin Ben-Eliezer, and the coordinator of civilian affairs in the area, Gen. Daniel Matt.

The scheduled meeting of the appeals board was postponed, presumably to allow Kawasme and Milhem to arrive in Israel in time. The mayors were reported to be in Rome but are expected to leave for Amman on Tuesday and proceed to the West Bank across the Allenby Bridge. It has not yet been decided whether they will be allowed to move freely in the occupied territories on the days they are scheduled to deliver their appeal or to attend public meetings.

It was unclear whether today's switch signifies a change in Israeli policy or whether it is just a technical move. Some West Bank Palestinians expressed optimism and hope that the mayors will now win their case. Interviewed on Israeli radio, Kawasme's wife Yurka said she is happy that her husband will now have a chance to defend himself in person.

Among Israelis the reaction was not unanimous. Knesset member Haim Druckman, leader of the orthodox nationalist group Gush Emunim, warned that the return of the two men could incite the West Bank after the relative quiet of the last five months. The mayors of other West Bank towns, however, said in an appeal to the military government that return of the mayors will bring further pacification of the area.

A major reason behind the determination of the Israeli government not to allow the deported mayors to return to the West Bank, even if only to present their case, was their extensive political activity since their expulsion, often in cooperation with the Palestine Liberation Organization of Yasser Arafat. They have been vociferous in denouncing Israeli policies in the occupied territories in Europe and the United States and were also given the floor at the U.N. Security Council. u