Isaac Herzog (L) speaks with Tzipi Livni, his co-leader of the center-left Zionist Union party, while campaigning outside a polling station in Modiin near Tel Aviv March 17, 2015. Millions of Israelis turned out to vote on Tuesday in a tightly-fought election, with Prime Minister Benjamin Netanyahu facing an uphill battle to defeat a strong campaign by the centre-left opposition to deny him a fourth term in office. When the last opinion polls were published on March 13, the centre-left Zionist Union led by Herzog held a four-seat lead over Netanyahu's Likud, a margin that had the opposition set for a surprise victory. REUTERS/Ronen Zvulun (ISRAEL - Tags: POLITICS ELECTIONS TPX IMAGES OF THE DAY)