Tzipi Livni could not get the ultra-Orthodox Shas party to join the coalition government.

It comes down to welfare payments to Orthodox schnorers^† and the status of Jerusalem, though, from what I’ve heard of Shas, my guess is that it was mostly about the welfare payments.

^*Benyamin, “The Craziest Motherf%$#er in the Middle East,” Netanyahu
^†Beggars or moochers.