Estimates by two Israeli broadcasters gave both sides 27 seats each in the 120-seat parliament, the Knesset.
Both would need support from other parties to form a governing coalition.
Israeli’s Prime Minister, Benjamin Netanyahu, has described the vote as a “great victory” for his Likud party, which was credited with a better result than anticipated.
However, Zionist Union, headed by Yitzhak Herzog, said the “spin” from Likud was “premature” and everything was “possible until the real results are in”.
Having stressed earlier that Israel public wants a change, he stated that while the final results were yet to be known, he would do all that he could to create a real socially minded government for Israel.