Blue and White chief Benny Gantz is meeting with fellow party leaders ahead of receiving the mandate to form the next government from President Reuven Rivlin.
Gantz is getting the mandate after Prime Minister Benjamin Netanyahu failed to form a majority coalition following the 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, 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.
Rivlin will officially mandate Gantz with the task at a ceremony at 8 p.m. at his residence.