Two weeks ago he had won a wafer-thin majority vote in the parliament that gave him first shot at trying to put together a coalition government.

Instead he has conceded to Netanyahu, who will remain prime minister for the next 18 months. Gantz is supposed to take over in late 2021, though Netanyahu has a formidable reputation for double-dealing.

Over the past year Gantz fought three hotly contested, though indecisive, general elections in which he vowed to bring down Netanyahu, who has ruled continuously for 11 years.

He had promised supporters he would never sit in a government alongside Netanyahu, who is due to stand trial on multiple corruption charges.

Predictably, the U-turn tore apart Gantz's Blue and White party. Denouncing the decision, two of the alliance's three constituent factions said they would head into the opposition.