Israel's president planned to task ex-military chief Benny Gantz with forming a new government Wednesday following Prime Minister Benjamin Netanyahu's failed attempts to do so after a deadlocked September election.

Gantz too is expected to face difficulties in forming a majority coalition despite expressing confidence he can reach a deal for a unity government.

He will have 28 days to try, and if he too fails, President Reuven Rivlin can ask parliament to agree on a candidate for prime minister.

If that too does not produce a new government, Israel could face yet another election -- a third in the space of a year.

Former military chief Benny Gantz is to be tasked with forming a new government in a landmark moment in Israeli politics as veteran incumbent Benjamin Netanyahu has been given the task after every election since 2009
Former military chief Benny Gantz is to be tasked with forming a new government in a landmark moment in Israeli politics as veteran incumbent Benjamin Netanyahu has been given the task after every election since 2009 AFP / Menahem KAHANA

Rivlin will officially mandate Gantz with the task at a ceremony at 8:00 pm (1700 GMT) at his residence.

It will be a landmark moment in Israeli politics since Netanyahu has been given the president's mandate to form a government after every election since 2009.

His decision to inform the president on Monday he could not form a government after the September 17 vote was by no means a sign he was ready to end his tenure as Israel's longest-serving prime minister.

The 70-year-old continued to strategise over how to remain in power, reportedly planning to meet with smaller right-wing and religious parties supporting him in parliament on Wednesday.

Netanyahu has not given up in his battle to retain the Israeli premiership, which he has held for a record total of more than 13 years
Netanyahu has not given up in his battle to retain the Israeli premiership, which he has held for a record total of more than 13 years AFP / Menahem KAHANA

While fighting to remain in the office he has held for a total of more than 13 years, Netanyahu also faces the possibility of corruption charges in the weeks ahead.

Gantz has not provided details of his strategy, but there were reports he planned to first reach out to Netanyahu's right-wing Likud to explore options for a unity government.

Both the Likud and Gantz's centrist Blue and White say they want a unity government, but they are divided on how to achieve it.

The Likud has been seeking to negotiate based on a compromise set out by Rivlin that takes into account the possibility the premier will be indicted in the coming weeks.

It could see Netanyahu remain prime minister for now, but step aside at some point later as he fights the charges.

Gantz would take over as acting premier under such a scenario.

Blue and White says Gantz should be prime minister first under any rotation arrangement since his party won the most seats, finishing with 33 compared to the Likud's 32 in the 120-seat parliament.

Gantz also says Blue and White cannot serve in a government with a prime minister facing serious indictment.

Israel