Israel's precarious coalition government was a step closer to collapse on Wednesday with politicians expected to approve a preliminary measure to dissolve parliament, raising prospects of elections next year. In a prime-time televised address on Tuesday, 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 is only a first step. A bill to dissolve the Knesset will require three additional successful readings before new elections must be called. Mr Gantz's decision to side with the opposition, at least for now, highlights the widening cracks in Israel's centre-right coalition, imperilled from the start by mistrust, infighting and public recriminations. "I had no illusions about Netanyahu," Mr 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. Mr Gantz said he decided to agree on a unity government with Mr Netanyahu, who he knew to be a "serial promise-breaker", because he wanted to spare Israelis "an ugly and costly" fourth election, especially because the coronavirus pandemic was accelerating. "Netanyahu didn't lie to me," Mr Gantz said. "He lied to all of you." The Netanyahu-Gantz coalition, established in April, included strict power-sharing arrangements. Mr Netanyahu, who heads the right-wing Likud party, was to serve as prime minister for the first half of the three-year arrangement. Mr Gantz had been scheduled to take over as premier in November 2021 but Mr Netanyahu's critics always insisted he would find a way to sink the coalition before vacating the prime minister's office for Mr Gantz. The unity deal included several triggers that would automatically force new elections, including a failure to pass a budget. Mr Gantz accused Mr Netanyahu of consistently misleading the public over the budget issue to serve his own political ends. "Netanyahu committed to pass a budget in August, and naturally did not stand by his word. He promised that it would happen in December and is not following through. Does anyone believe him any more?" Mr Gantz said. Mr Gantz directly called on Mr Netanyahu to "put a state budget forward", making clear that if he did so, new elections could be avoided. Mr Netanyahu released a video shortly before Mr Gantz spoke on Tuesday, urging him to keep the coalition together. "Now is not the time for elections," Mr Netanyahu said. "Now is the time for unity." Mr Gantz courts huge political risks by taking Israel back to the polls. His Blue and White coalition fractured when he decided to strike a deal with Mr Netanyahu and Mr Gantz's personal popularity has fallen, according to a series of recent polls. His former ally turned critic, Yair Lapid of the Yesh Atid party, is now the Knesset opposition leader and would be seen by many voters as a more effective anti-Netanyahu force than Mr Gantz in a new election. In a commentary on Israel's N12 website, political columnist Amit Segal argued that Mr Gantz's political fortunes were plummeting. Blue and White was "never going to revert to being a government alternative", Mr Segal said. "The party can only expect a nightmarishly difficult election campaign."