Yair Lapid is to become Israel's interim prime minister on Friday, after parliament disbanded itself ahead of new elections.
Mr Lapid, leader of a centrist party, will take over at midnight (21:00 GMT Thursday) from Naftali Bennett.
They agreed to rotate office when they formed an unlikely eight-party coalition after last year's election.
However it collapsed last week, clearing the way for fresh polls - the fifth in less than four years.
In a mark of the bitter divisions in Israel's parliament (Knesset), even the bill to dissolve it was repeatedly delayed. The new elections will be held on 1 November.
Israel has seen a record-setting cycle of elections as parties time and again failed to secure enough seats to form a governing coalition with a majority. The Lapid-Bennett coalition temporarily broke the stalemate.
The upcoming round also creates an opening for Israel's longest-serving prime minister, Benjamin Netanyahu, to return to office despite being on trial on corruption charges, which he denies.
Mr Netanyahu, whose right-wing Likud party is forecast to remain the largest in the Knesset, was ousted by Mr Bennett and Mr Lapid last June.
Mr Bennett has said he will not be standing in the November election. He will occupy the position of alternate prime minister until then.
Mr Lapid, a 58-year-old former TV news anchor, will serve as caretaker prime minister until the next government is formed.
He was tasked last May with forming the now-outgoing government after Mr Netanyahu and his allies were unable to secure a majority in the wake of the March 2021 poll.
Mr Lapid agreed to rotate the premiership, with Mr Bennett taking office first as part of a deal that brought together the coalition. Mr Bennett had been due to hand over power to him in September 2023.
The government was the most diverse in Israel's history, comprising eight parties from across the political spectrum - including those with ideologically opposing views. It also contained an independent Arab party for the first time since the state was established in 1948.
Despite Mr Bennett's attempts to focus only on issues where parties could work together, it started to fray towards the end of its first year, becoming a minority government when a member of Yamina quit earlier this month.
In an emotional TV address last week, Mr Bennett said he and Mr Lapid had "turned over every single rock" to try to keep the coalition going, but that they had run out of options.
Mr Netanyahu welcomed the announcement as "great news for millions of Israeli citizens".
Polls currently indicate that his party will take most seats in a new election but will still struggle to form a governing majority with its religious and nationalist allies.
The prospect of a further period of political uncertainty comes at a sensitive time, as Israel faces the challenges of rising living costs, an upsurge in violence in its conflict with the Palestinians, and renewed international efforts to revive a nuclear deal with Iran - something which alarms Israel.