Civil unrest between Jews and Arabs in Israel dealt a strong blow on Thursday to efforts by Prime Minister Benjamin Netanyahu's main political rival Yair Lapid to form a new government and unseat the Israeli leader.
Naftali Bennett, head of the ultranationalist Yamina party and a kingmaker after an inconclusive March 23 parliamentary election, said he was abandoning coalition talks with Lapid, the opposition leader, preferring a wider unity government.
Lapid, who heads the centrist Yesh Atid party, has three weeks left in a 28-day mandate from Israel's president to try to form a governing coalition. If he fails, a new election - Israel's fifth in two years - is likely.
A "rotation" deal in which Lapid and Bennett would take turns as prime minister had been mooted, but it would need the backing of Arab legislators for a parliamentary majority.
Bennett was quoted by Israeli media as saying the current strife with Israel's 21% Arab minority would make such a government unfeasible.
Israel-Gaza cross-border hostilities have been accompanied by violence in mixed communities of Jews and Arabs in Israel. Synagogues have been attacked and street fights have broken out, prompting Israel's president to warn of civil war.
Mansour Abbas, who heads the United Arab List party, said on Channel 12 TV that Bennett phoned him to say a so-called "government of change" with Lapid, leader of the centrist Yesh Atid faction, was now "off the table".
In a televised address, Lapid voiced regret at Bennett's decision but said he would continue his efforts to put together a coalition.
Israeli political commentators gave him little chance of success.