Sheik Mohammed Abu Rabia, the only Bedouin member of Israel's parliament and a forceful opponent of expropriation of Arab land in the Negev Desert, was shot to death in an ambush tonight as he sat in his car near a West Jerusalem hotel.

Abu Rabia was the first member of Israel's parliament to be assassinated since the founding of the country 33 years ago.

Police said that a military-type jeep, apparently driven by civilians, pulled alongside his car and two gunmen fired into the front and side windows before speeding away. Abu Rabia had been living in the nearby Holy Land Hotel while parliament was in session.

A respected physician who lived in Beersheva, Abu Rabia was elected to parliament in 1977 on his own Bedouin Rights ticket, but he struck a deal with other Arab candidates to alternate terms in office during the four-year session.

Seif Eiden Zouabi, a Christian Arab from Nazareth, served the first part of the shared term, and Abu Rabia took over in 1978, using parliament as a forum to oppose a controversial Israeli land acquisition bill that was adopted for the construction of two new airbases in the Negev desert following the return of the Sinai Peninsula to Egypt.

Another Israeli Arab politician, Sheik Jaber Mohadi, was to have succeeded Abu Rabia, according to an agreement before the 1977 election, but Abu Rabia reportedly refused to give up his seat.

Israeli police sources said no motive for tonight's shooting had been established, but that the dispute over relinquishing the parliamentary seat was being investigated.

Abu Rabia reportedly had told associates in parliament that he wanted the government to provide bodyguards because of the threats on his life.

Abu Rabia, the first Bedouin to graduate from medical school in Israel, had been widely known in the Negev as "the Bedouin doctor," and he had organized numerous protests against Israeli land acquisition policies in the desert.