Forecast to win up to 24 seats to Likud's 21 in the 120-member parliament, Zionist Union hopes the gap will be wide enough to persuade Israel's president to ask its leader, Labour party chief Isaac Herzog, rather than Netanyahu, to try to form a coalition government after Tuesday's balloting.
"If we don't close the gap in the coming days, there is certainly a risk that Tzipi Livni and Bougie Herzog will be the next prime ministers," Netanyahu told Channel 2 in one of two primetime television interviews, using Herzog's nickname.
Under his Zionist Union alliance with centrist Livni, Herzog would serve as Israel's leader for two years and then hand over to the country's most prominent woman politician for the remainder of their government's slated four-year term.
Netanyahu also ruled out the possibility of forming a broad coalition after the election that would include a leadership rotation between him and Herzog.
In the right-leaning Jerusalem Post and the Israel Hayom free sheet, an ardent supporter, Netanyahu focused his message on Israelis who want him as prime minister but plan to vote for his potential partners in a Likud-led coalition.
Gilad Erdan, a Likud cabinet minister and Netanyahu confidant, said he expected the prime minister to give interviews to other Israeli media outlets in the next few days as part of an effort to bring "supporters of Likud and its ideological path back to their (rightful) home".