Yuval Zellner Party, Zellner joined Kadima in 2005. Ranked 34th on Kadima's list for the 2009 elections, he failed to win a seat, but entered the Knesset on 3 May 2012 as a replacement for Tzipi Livni, who had resigned her seat after losing the party's leadership election to Shaul Mofaz. Placed sixth on the Kadima list for the 2013 elections, he lost his seat when the party was reduced to two MKs. However, he returned to the Knesset on 18 December 2014 following Yisrael Hasson's resignation and other resignations from the party list. The party did not contest the 2015 elections,
Tzipi Livni the UN Security Council was influenced by his talks with Livni and former president Shimon Peres, who said such a move could serve the political interests of those opposing the peace process. After the dissolution of the Knesset in December 2014, Labor leader Isaac Herzog and Livni announced a joint slate between Labor and Hatnuah, called the Zionist Union, to contest the 2015 elections in an effort to keep Netanyahu, leader of the Likud Party, from securing a fourth term as prime minister. They proposed to share the role of prime minister (an arrangement known in the Knesset as rotation)