Former military chief Gadi Eisenkot speaks after receiving a mandate to form a government from Israeli President Isaac Herzog at the president's residence in Jerusalem, Israel, on Sunday. | BLOOMBERG

Israeli election challenger Gadi Eisenkot got the first attempt at forming a new government, putting him a step closer to ending Prime Minister Benjamin Netanyahu’s record tenure.

Eisenkot was formally handed the mandate on Sunday by Israeli President Isaac Herzog, who noted the “immense” challenges facing the country. Eisenkot will have up to six weeks to try to form a coalition that accounts for the majority of 120 parliamentary seats. Failure would mean the task likely reverts to Netanyahu, who for now continues to govern in a caretaker capacity.

While neither candidate’s political camp won a clear parliamentary majority in the Oct. 27 vote, Eisenkot’s nomination was supported by a majority of parties.…