Prime Minister Benjamin Netanyahu’s chief rival said on Monday that he had agreed with a smaller party to try to form a new government after elections last week.
The announcement by Benny Gantz, leader of the Blue and White Party, dealt a new setback to Mr Netanyahu as he struggles to hold on to power before his trial on corruption charges.
In a statement, Mr Gantz said that he had a good meeting with Avigdor Lieberman, leader of the small Yisrael Beiteinu party.
“We discussed questions of fundamental principle and determined that we will work together to assemble a government that will pull Israel out of the political deadlock and avert a fourth round of elections,” Mr Gantz said.
In last week’s election, Israel’s third in less than a year, Mr Netanyahu’s Likud emerged as the largest party.
But with his smaller religious and nationalist allies, he secured only 58 seats in Parliament, short of the 61-seat majority needed to form a new government.
Mr Netanyahu’s opponents, led by Mr Gantz, control most of the seats.
But beyond their shared animosity towards the incumbent, there are deep divisions between these parties, which include Mr Lieberman’s secular, ultranationalist party and the Arab-led Joint List.
Mr Gantz’s announcement with Mr Lieberman marked a step towards unifying those forces, although it is unclear whether they can reach a final agreement, much less a deal with Arab politicians.
Mr Lieberman has in the past called Arab political leaders in Israel "terrorist sympathisers".
“We’ll continue to discuss the details, formulate our common objectives and move forward,” Mr Gantz said.
On the campaign trail, he ruled out a partnership with the Joint List, whose support is rooted in Israel’s Arab minority.
But after a bruising campaign characterised by nasty personal attacks from Mr Netanyahu and his supporters, and fearing further deadlock if the country is forced into another election, Mr Gantz has left the door open.
After his meeting with Mr Lieberman, Mr Gantz spoke to Ayman Odeh, leader of the Joint List, and other senior Arab politicians.
“Gantz repeated his commitment to forming a government that will serve all of Israel’s citizens, Jews and Arabs alike,” his party said.
Mr Netanyahu is desperate to remain as prime minister as he prepares to go on trial on March 17.
He has been charged with fraud, breach of trust and accepting bribes in connection to scandals that include accepting expensive gifts from wealthy friends and offering to exchange favours with powerful media moguls.
The long-ruling Israeli leader denies any wrongdoing.
Mr Netanyahu’s lawyers have requested a delay in the start of the trial, saying they need more time to review evidence.
Prosecutors on Monday said they opposed any delays.
Israel’s president, Reuven Rivlin, must decide by next week who to choose as the prime minister-designate.
The president typically chooses the candidate he deems has the best chance of forming a governing coalition.
That is usually the leader of the largest party, in this case Mr Netanyahu.
But if Mr Rivlin believes Mr Gantz has a better chance, he could give the former military chief the first chance to gather a coalition.
Mr Rivlin’s office announced that he would hold one day of consultations with the eight parties elected to Parliament next Sunday before he makes his decision.
Each of the parties is to tell him who they support.
An endorsement from Mr Lieberman, who had refrained from taking sides during the earlier two elections, would increase Mr Gantz’s chances of success.
Mr Lieberman is a former Netanyahu ally who has become a tough rival and appears to be bent on toppling his former mentor.
He has expressed support for a new bill that would ban an indicted politician from forming a new government after an election.
Mr Netanyahu has defiantly insisted he won last week’s election and accused his opponents of trying to “steal the elections” by aligning with Arab-led parties, which he claimed were hostile to the state.
Last week, he said the Joint List should not even be “part of the equation” of Israeli politics, drawing new charges of incitement and racism from his opponents.
“I promise you, I am not going anywhere,” Mr Netanyahu said at the weekend.