Israeli Prime Minister Benjamin Netanyahu delivers a statement on Iran's nuclear weapons development site in Jerusalem, on Sept. 9, 2019. (Xinhua/Gil Cohen Magen)

Israel's precarious coalition government was set to move closer toward collapse on Wednesday with lawmakers expected to approve a preliminary measure to dissolve parliament, raising prospects of elections in 2021.

In a primetime televised address on Tuesday, Alternate Prime Minister Benny Gantz, the key coalition partner of Prime Minister Benjamin Netanyahu, said his centrist Blue and White party would back a bill to dissolve the Knesset, Israel's parliament.

But Wednesday's parliamentary vote on an opposition proposal marks only a first step.

A bill to dissolve the Knesset will require three additional successful readings before new elections must be called.

But Gantz's decision to side with the opposition, at least for now, highlights the widening cracks in Israel's center-right coalition, imperilled from the start by mistrust, infighting and public recriminations.

"I had no illusions about Netanyahu," Gantz said in his Tuesday speech.

He reminded Israelis that he battled the prime minister in three consecutive inconclusive elections that did not allow either leader to form a majority government.

Gantz said he decided to agree a unity government with Netanyahu, who he knew to be a "serial promise-breaker," because he wanted to spare Israelis "an ugly and costly" fourth election, especially as the coronavirus pandemic was accelerating.

The Netanyahu-Gantz coalition, agreed in April, included strict power-sharing arrangements.

Netanyahu was to serve as prime minister for the first half of the three-year arrangement.

AFP