Israeli opposition leader Yair Lapid, who has been given 28 days to form a government, has said his goal is to forge a coalition that ends Prime Minister Benjamin Netanyahu's divisive rule.

But doing so will require walking a tightrope unrivalled in Israeli political history.

Lapid will have to build a coalition united primarily by opposition to Netanyahu from disparate groups ranging from right-wing Jewish nationalists to Arab lawmakers who have never before sat in an Israeli government.

And, in an unprecedented twist, the centrist former television anchor will probably have to sacrifice his own prime ministerial ambitions at least in the short term.

Israel's fourth inconclusive election in less than two years produced a fractured parliament.

Lapid can likely count on the support of centrist and left-wing lawmakers as well as two right-wing parties firmly committed to removing Netanyahu.

Israeli opposition leader Yair Lapid has been given the chance to end Prime Minister Benjamin Netanyahu's record 12 straight years in office but to do so he must bring together the most unlikely of bedfellows Israeli opposition leader Yair Lapid has been given the chance to end Prime Minister Benjamin Netanyahu's record 12 straight years in office but to do so he must bring together the most unlikely of bedfellows Photo: AFP / GIL COHEN-MAGEN

The New Hope party is made up of defectors from Netanyahu's right-wing Likud, while Yisrael Beitenu is backed by many immigrants from the former Soviet Union.

Barring defections, those parties would give a Lapid colaition 51 of the 61 seats in pariament it needs for majority.

Netanyahu's Likud, two ultra-Orthodox Jewish parties and the far-right Religious Zionism alliance collectively hold 52 seats and would almost certainly rebuff any outreach from Lapid.

To reach the magic number of 61, Lapid has to draw in Naftali Bennett's religious nationalist Yamina party, which holds seven seats, and at least some Arab lawmakers, an ideologically diverse group belonging to different parties that collectively hold 10 seats.

There is general consensus that Lapid's path to power requires offering Bennett first turn at a rotating prime ministership as part of coalition deal.

Lapid has already made such an offer to Bennett, a former Netanyahu protege whose relationship with the premier has disintegrated.

Timeline of main developments in Israel's political deadlock in 2019. Timeline of main developments in Israel's political deadlock in 2019. Photo: AFP / Gal ROMA

"The only viable option is Bennett-Lapid with Bennett going first," said Gayil Talshir, political scientist at Hebrew University.

The logic of the strategy, is that it brings key kingmaker Bennett on board and makes the coalition more palatable to right-wingers, especially in New Hope.

It could also appeal to the centre and left by accomplishing something that has eluded them since 2009: removing Netanyahu from power.

"Lapid must postpone his dream of being prime minister," in order to have a chance of reaching 61 seats, political analyst Shmuel Rosner told AFP.

The Lapid-Bennett rotation plan could easily crumble in the hornet's nest of Israeli politics.

Bennett has enthusiastically backed Jewish settlement expansion in the occupied West Bank, a red line for Arab lawmakers firmly committed to Palestinian statehood.

Lawmakers from the Arab-led Joint List reiterated their support for a potential Lapid government on Wednesday, but told President Reuven Rivlin in writing that they "do not support a government headed by Naftali Bennett."

Mansour Abbas, head of the Islamic conservative Raam party, which has four seats, has generally voiced openness to any arrangement that improves living conditions for Israel's 20 percent Arab minority.

But now that he has been given a chance to form a government, Lapid still has no obvious way of bridging the Bennett-Arab divide.

Perhaps the most serious threat to a unity government is Netanyahu himself.

Moments after Lapid was tapped, he made a television address directed at right-wingers alleging Bennett was about to sell them out to achieve his prime ministerial ambitions.

"Everyone knows (Bennett) wants to form a dangerous left-wing government," Netanyahu charged without evidence.

Politics experts agree that Netanyahu will now commit himself to making it uncomfortable for any right-winger to join a pro-Lapid government.

"Netanyahu is now in full sabotage mode," said the headline in the centre-left Haaretz newspaper.

Talshir said there was already "humongous pressure on Bennett's people to defect or to abstain," when asked to support a government formed under Lapid's mandate.