Only once in the history of Israeli politics has a party other than Likud or Labour formed the government. That was Ariel Sharon’s Kadima in March 2006. But by then the party’s founder had been in a deep coma for nearly three months and even as his heirs celebrated their victory, the leader’s absence already signalled their ultimate downfall.

Breaking the Likud-Labour hegemony has long been the holy grail of Israeli politics. Knesset history is littered with centrist parties which were founded with great fanfare, only to sink and disband within one or two terms. Kadima is just about still around after barely scraping over the electoral threshold last January with only two MKs.

Still, Kadima remains the only true success story of the political centre in Israel, while Likud and Labour, despite suffering defeats over the last decade, continue to soldier on as parties of power and opposition and occasionally partners in national unity coalitions.

Just over eight years ago it seemed that the long-awaited big-bang had finally taken place. Not only had Prime Minister Ariel Sharon, at the height of his national and international popularity, broken with the fractured and rebellious Likud, taking with him heavyweight Likudniks such as Tzipi Livni, Ehud Olmert, Meir Sheetrit, Shaul Mofaz and Tzahi Ha-Negbi, and Labourites Chaim Ramon, Dalya Itzik and above all, the former prime minister and Labour leader Shimon Peres. Powerful mayors, ex-generals and public figures also flocked to join the party along with tens of thousands of ordinary citizens.

The polls promised the party at least a third of the seats in the next Knesset and coalition. But six weeks and two strokes later, Sharon was gone and under the leadership of the unpopular Ehud Olmert, Kadima won just 29 seats — enough to form a coalition, but distinctly fewer than it expected under Sharon. This was not the end of Kadima — it came first in the 2009 elections under Tzipi Livni, but it had lost its commanding position in the Knesset and was forced by Benjamin Netanyahu into opposition, where it rapidly ate itself into its current obscurity.

Sharon’s strength was Kadima’s only tangible asset. It is tantalising to speculate what he could have wrought at the head of a Kadima-dominated government, but in his absence, the party’s demise was all but assured. The dream of a true centrist party breaking the deadlock remains just that.