Israeli Prime Minister Benjamin Netanyahu has alleged, without providing evidence, that Arab parties' record gains in an election this week were driven in part by voter fraud, a charge rejected by Arab leaders who accused the premier of incitement.
The allegation represents an escalation of rhetoric against Arab parties by Netanyahu and his far-right partners after high Arab turnout in a national ballot on Tuesday effectively blocked a smooth path to power for either him or his main rivals.
Israeli officials said on Thursday, local time, that the authorities were probing fraud allegations, though the election's integrity was not systematically compromised.
Analysts and critics say that by stepping up attacks on Arab parties, Netanyahu may be trying to ensure his main rival, Gadi Eisenkot, feels unable to even consider forming a minority government with Arab help that could oust him from power.
Netanyahu's goal is "delegitimising any Arab-Jewish cooperation", said Eytan Gilboa, professor of politics at Reichman University.
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Tuesday's tightly fought election has produced no clear winner and is likely to be followed by weeks of protracted negotiations over a new government.
With nearly 99 per cent of votes counted, Netanyahu's nationalist-religious bloc held a modest lead in seats over a bloc of right-wing and centre-left parties led by Eisenkot, with both men's coalitions short of the 61 seats needed for a majority in parliament.
Parties representing Israel's 21 per cent Arab minority were projected to win an unprecedented 19 seats, leaving Eisenkot's bloc, which has 48 seats against Netanyahu's camp of 53, with no path to power without broad Arab backing.
Eisenkot has so far ruled out including the parties in government but his camp could try to form a minority government with Arab support from the outside.
Ahmad Tibi, one of the leaders of the Arab Joint List party, said Netanyahu has launched a "toxic campaign" meant to undermine the election results.
"This entire campaign is directed against Eisenkot, to prevent him, intimidate and scare him off forming a government that relies on external support from the Joint List or Ra'am," Tibi told Reuters.
During and after Tuesday's election, Netanyahu and his allies warned against rising Arab turnout and his right-wing Likud party issued statements accusing the Arab parties of "stealing the vote".
It demanded police and the Shin Bet domestic intelligence service investigate incidents of suspected election bribery and intimidation at ballot stations in Arab towns. It said it possessed evidence of such activity but has not presented it to the public.
The police say they have arrested at least seven people since Tuesday in Israel's south, where many Arabs live, on suspicion of voter fraud.
On Thursday, the head of Israel's Central Election Committees, Supreme Court jurist Noam Sohlberg, said he had asked the Shin Bet to investigate suspicions that unidentified foreign players had tried to intervene in the election.
Likud seized on Sohlberg's request, alleging an attack on Israel's democracy, "an Islamisation of Israel and the toppling of the right-wing in order to bring about IDF withdrawal and defeat on all fronts, foremost Iran".
Likud said Qatar was behind the alleged election intervention, which Qatar denied.
Ra'am head Mansour Abbas said his party was not involved and urged a full investigation.
"We have one message in response to the campaign of incitement and delegitimisation [Netanyahu] is waging against Arab citizens: Nothing will come of it, because there is nothing there," Abbas said in a statement.
In a letter sent to a parliamentarian and published by the Central Election Committee, the committee said that there was "no base for claims that there was systematic harm to the election's integrity".
Shin Bet said that its investigation was focused only on those involved and should not cast aspersions on "an entire sector that went out to vote democratically and legally".
