Israeli President Isaac Herzog must choose Sunday who gets the first chance to form a government after an inconclusive October election left both Prime Minister Benjamin Netanyahu and former army chief Gadi Eisenkot short of a 61-seat parliamentary majority.

Eisenkot received backing from 67 of 120 Knesset members during party consultations that ended Thursday, including support from Palestinian-led parties. Netanyahu received only 46 endorsements after United Torah Judaism, a longtime coalition partner, withheld support over the government's failure to exempt ultra-Orthodox Israelis from military service.

Netanyahu's right-wing and religious bloc holds 53 seats. Four Jewish-led opposition parties backing Eisenkot hold 48 seats. Palestinian-led parties hold 19 seats total. The Joint List holds 11 and the United Arab List holds eight.

Eisenkot has ruled out bringing Palestinian-led parties into his government, though the Joint List has said it would back him from outside parliament, and Ra'am has signalled willingness to join. Eisenkot has said both groups must recognize Hamas as a "terrorist organisation," a condition Palestinian leaders have resisted. Ra'am leader Mansour Abbas expressed support for disarming Hamas but declined to label it a terror group.

Israeli law allows Eisenkot to form a minority government with fewer than 61 seats if it wins a confidence vote, which the Palestinian-led parties could help him secure. He could then later gain a majority by offering the ultra-Orthodox parties concessions on military conscription.

Netanyahu would need to lure opposition lawmakers to his side or negotiate a rotating prime minister arrangement, options many rivals have ruled out. A failed government formation would result in a new election within 90 days, keeping Netanyahu as caretaker prime minister. Analyst Nehru Jamhour told Al Jazeera that a drawn-out impasse and new election was the likeliest outcome and Netanyahu's preferred scenario.

Herzog will grant the chosen nominee 28 days to form a coalition, extendable by 14 more.