The incumbent Prime Minister, whose Likud party came out as surprise winners, urged the voters via Facebook on Tuesday evening to support his right-wing government because Israeli Arabs were going "en masse to the polls."
"The votes for Netanyahu rose late in the day in response to the warnings about Arab voters heading to the polls," Herzog said in a radio interview, according to the Jerusalem Post.
"The results here are not just a victory for Netanyahu, they are actually a victory for hate and fear," Zionist Union's co-leader Tzipi Livni was quoted as saying by the Jerusalem Post.
Prior to the vote, Netanyahu said, in response to consistent polling showing his party would lose seats, that he would oppose the creation of a Palestinian state if reelected. The center-left Zionist Union, in turn, promised to seek an agreement with the Palestinians.
Prime Minister Netanyahu must put together a coalition of 61 lawmakers to have a majority in the 120-seat parliament, called the Knesset, before forming a new government.
More than 4 million Israelis, or 71.8 percent of eligible voters, cast their ballots on Tuesday, making it the highest turnout since 1999.