TEL AVIV—Israeli Primary Minister Benjamin Netanyahu delayed the swearing in of his new unity federal government till at the very least Sunday because of a final-moment dispute inside of his Likud party around the allotment of ministries, extending political uncertainty in the nation.

Mr. Netanyahu, the country’s longest-serving chief, and his previous rival, Benny Gantz, agreed final month to variety a unity federal government soon after 3 inconclusive elections in a 12 months.