Israeli Prime Minister Benjamin Netanyahu informed the country's president Monday he could not form a new government following deadlocked September elections, making way for his opponent Benny Gantz to try.
"A short time ago I informed the president that I was handing back my mandate to try to form a government," Netanyahu said in a video posted on his official Facebook page.
The prime minister blamed Gantz for refusing to negotiate on Netanyahu's preferred terms.
President Reuven Rivlin said shortly afterwards that he intended to ask ex-military chief Gantz, head of the centrist Blue and White alliance, to try to form a government.
He too will have 28 days to attempt to do so, and will also face long odds.
Efforts to form a unity government after the polls - the second since April - have so far failed.
Blue and White said in a statement that "the time of spin is over, and it is now time for action".
"Blue and White is determined to form the liberal unity government, led by Benny Gantz, that the people of Israel voted for a month ago," it said.
By "liberal", it signalled it would seek to limit the influence of religious parties in forming a coalition