Israeli President Isaac Herzog on Saturday night handed former military chief Gadi Eisenkot the first opportunity to form Israel's next government, dealing a major blow to Prime Minister Benjamin Netanyahu's bid to stay in power after an election that left no political bloc with a parliamentary majority.

Herzog's decision followed two days of consultations with every party elected to the Knesset. Eisenkot secured the backing of 67 of the 120 incoming lawmakers, against 46 for Netanyahu, with seven recommending no candidate at all.

The mandate will be formally handed over on Sunday afternoon at the President's Residence in Jerusalem, where Eisenkot is due to receive it at 5pm local time. From that moment he will have 28 days to assemble a coalition, with a possible 14-day extension, giving him up to six weeks in total.

The October 27 election produced a fractured result. Netanyahu's Likud emerged as the largest single party with 27 seats, but his wider religious-nationalist bloc managed only 53 seats, eight short of the 61 needed for a majority. Eisenkot's centrist Yashar party won 21 seats, the second-largest haul, and his allied parties together hold 48. The two Arab-majority parties won a combined 19 seats, an unprecedented showing that has left them holding the balance of power.

Eisenkot, 66, is a retired military chief who once led the Israel Defense Forces and entered politics as the main challenger to Netanyahu. He has framed the moment as a national emergency, writing on X shortly after Herzog's announcement: "This is the time to establish a national emergency government. I will do anything possible to prove us worthy."

He is pushing to form what he calls a national emergency government and to swear in a minority government as soon as possible. He has set four conditions for any partner: recognition of Israel as a Jewish, democratic, liberal and egalitarian state; commitment to the values of the Declaration of Independence; universal service, whether military, national or civilian; and recognition of Hamas as a terrorist organisation.

The arithmetic, however, is far from simple. Israeli law requires only a simple majority to establish a government, but removing one needs an absolute majority of 61 lawmakers backing an alternative. Eisenkot's 67 recommendations include 19 from the two Arab parties, support he may need but which several of his own allies have resisted relying on, fearing a backlash from their own voters. His central obstacle is Avigdor Liberman of Yisrael Beiteinu, and his first test comes on Tuesday, when the new Knesset is sworn in.

Netanyahu has spent the days since the election campaigning to head off any alliance between Eisenkot and the Arab-led parties, including unsubstantiated claims that the Arab parties "stole" the election. Shortly before Herzog's announcement, he called in a video statement for a "national unity government" and warned against "hastily swearing in a government with terrorist supporters". Yashar hit back with a statement of its own on X.

The contest is unfolding in a deeply divided country still reeling from the October 7, 2023 Hamas-led attacks and the three years of war in Gaza and beyond that followed. Netanyahu is Israel's longest-serving prime minister, and if Eisenkot succeeds in building a coalition, it would bring that long hold on power to an end.

What happens next is a month of hard bargaining over cabinet posts, budgets and policies. If Eisenkot fails to put a coalition together, the mandate passes to Netanyahu for another four weeks. The whole process carries a deadline of roughly 100 days, after which Israel would return to the polls, a prospect neither side wants but one that remains real if no government can be formed.