Israeli Defence Minister Ehud Barak's abrupt retirement from politics caused a shock to the general election campaign but left many predicting his immediate return to office.
Barak, 70, said in Tel Aviv he would not seek re-election in January and would retire when a new Government was formed, probably in three months.
He has held the role for seven years, completing three terms under three governments and was Labour Prime Minister from 1999 to 2001.
Barak said he wanted to spend more time with his family and had now had enough of politics, "something for which I never had any special desire in the first place ..."
Barak unseated Benjamin Netanyahu in 1999, but the two formed a close partnership after Netanyahu's re-election as Prime Minister in 2009. The former rivals were united in military policy.