Crossing through the security checkpoint that divides Jerusalem’s West from its East, you notice the differences immediately. Gone are the Israel Defense Forces T-shirts and the little white and blue flags, replaced by keffiyeh scarves, with shops selling spices and ‘Free Palestine’ badges. You’ve left one world, and gone into another.

Israel’s Prime Minister, Benjamin Netanyahu, may soon be feeling something similar. After more than a decade at the helm, and a global outcry sparked by right-wing Jewish settlers’ claims in the Arab-run half of the city, a new coalition of opposition parties has become the most serious challenge in the history of his crisis-hit premiership. Facing corruption charges at home and international consternation over the offensive against militants in Gaza, Netanyahu might now have run out of road.

A last-ditch effort to keep the current administration together failed last week, when a court threw out a legal challenge against his rivals, who have announced they have the numbers in parliament to form a government themselves. Right-wing figurehead Naftali Bennett, his own former defense minister, has partnered with centrist opposition leader Yair Lapid in a bid to swing the balance against the government.

Bennett and Lapid are now pushing for a swift vote in the Knesset to oust Netanyahu and send his party, Likud, into opposition. The coalition they have built behind them would be arguably the most diverse and tenuous to take power anywhere in the world. As well as Lapid’s liberal Yesh Atid and Bennett’s nationalist Yamina, their putative bloc includes leftists, greens and even the United Arab List (UAL) – which would make history as the first time a group representing Palestinian citizens of Israel entered into government.

Crucially, the challengers have managed to peel Likud’s governing partner, Blue and White, away from the ruling coalition. Benny Gantz, the faction’s leader, had been seen as the most promising challenger to Netanyahu in previous elections, and had agreed to prop up the administration only on the condition that he be sworn in as an alternate prime minister under a power-sharing agreement, which depended on other parties being unable to agree on an alternative. Avigdor Lieberman, whose party represents the sizable Russian-Israeli community, is also backing the bid, having previously been seen as the country’s kingmaker in past fraught negotiations.

Yet the campaign to oust Netanyahu is far from stable. While its political and ethnic diversity has been billed as a show of unity in the deeply divided country, it could also mean the coalition falls apart at the first hurdle – potentially even before it can form a government. Despite almost the entire opposition backing the bid, the challengers would only have 61 seats out of 120. In short, they need every single vote just to oust the current administration. Given party loyalty is hardly a feature of Israeli politics, if Netanyahu is able to strike a deal to peel off just one or two politicians, the dethroning could fall flat.

Even if they are able to form a government, the opposition parties are disunited on basic questions of domestic and foreign policy, from the status of Jerusalem’s holy sites to the controversial plans of right-wing settlers to evict Palestinian families from land owned by Jewish groups in East Jerusalem that brought about the current crisis. A major incident like a terrorist attack or a resumption of the rocket barrages from militant-controlled Gaza could cause an irreconcilable split that would see the ruling block to collapse, unable to agree on a response to a serious security issue.

Its failure would see Israel hurtle towards a fifth national election in just two years, with no guarantees that a weary and politically tribal population would side with the fragile big-tent government. In fact, the prospects of success at the ballot box for such a bloc seem slim, with right-wing voters for the more populist factions likely to take a dim view of their decision to enter into a coalition with Arab parties. At the same time, Palestinian activists have slammed the head of the UAL, Mansour Abbas, as having “made the big mistake of thinking he could be an Israeli kingmaker”. The criticism, it seems, is coming from all sides.

As Netanyahu and his allies work furiously to splinter the fractious clique and retain their hold on the levers of power, the world has begun to contemplate the prospect of politics in the Middle East without one of its most resilient and controversial figures.

Yet the chances for imminent change are unlikely. Bennett, who stands to take the top job if the challenge succeeds, is cut from the same political cloth as his potential predecessor. He has carved out a reputation by taking a tough and uncompromising stance in dealing with Palestinians, having himself lived in settler communities in the West Bank and supporting their growth in the face of near-universal condemnation abroad.

The populist leader would also be the first prime minister in Israel’s entire history to define himself as a religiously-driven politician, undermining the country’s long-standing policy of maintaining it is a secular Jewish state. Faith has often played a role in the country’s politics, with ultra-Orthodox Jews, liberal synagogues and Muslim citizens often voting in blocs. The established policy of official impartiality to the deep-rooted divisions in the Holy Land has been one of the main contributors to ensuring these differences don’t spill over into outright hostility.

Bennett’s unlikely rise as the head of a multi-ethnic political coalition would have been impossible were it not entirely formed in opposition to Netanyahu. It is obvious what those behind the revolt stand against, but what they actually stand for is far less clear. The existential rifts in their positions on any given issue have remained unspoken, and their prospective programme for government undecided. What matters to them now is winning the struggle in parliament – convincing voters and deciding policies can be left for another day.

With the all-important confidence vote billed for the coming days, it remains to be seen whether the centre can, in fact, hold in the campaign to replace Israel’s long-time leader. While photographs emerged online last week purporting to show removal men already taking the Prime Minister’s possessions out of his official residence and into his family home, Israelis are under no illusion about their leader’s staying power after weathering years of scandal and insurrection. Even for those politicians behind the bid to oust him, it seems few are daring to imagine life after Bibi.