Prime minister´s office says Shimon Peres should not speak out on Iran as he is too prone to mistakes

The faultlines among Israel´s leaders over whether to take unilateral military action against Iran´s nuclear capability have deepened, with a prime ministerial aide launching a stinging public rebuke to President Shimon Peres after he said that the country should not act alone.

"Shimon Peres forgets what the role of the president of Israel is," an official from Binyamin Netanyahu´s office was quoted in the Israeli media as saying.

The row – a stark example of the sharp disagreements at the heart of Israel´s political, military and intelligence establishment over the issue – came as Iran´s president, Mahmoud Ahmadinejad, said Israel´s existence was "an insult to all humanity".

In a speech to mark al-Quds Day on the last Friday of the Islamic holy month of Ramadan, Ahmadinejad told a rally in Tehran that "the Zionist regime and the Zionists are a cancerous tumour" and warned against "one cell of them [being] left in one inch of [Palestinian] land in the future".

He added: "The nations of the region will soon finish off the usurper Zionists in the Palestinian land … A new Middle East will definitely be formed. With the grace of God and help of the nations, in the new Middle East there will be no trace of the Americans and Zionists."

The Iranian president has traditionally used al-Quds Day, on which rallies in support of the Palestinian people are held in many Muslim countries, to deliver invective against Israel.

His words will inevitably be used to bolster arguments in favour of military action to prevent a nuclear-armed Iran. Speculation has intensified recently that Netanyahu and defence minister Ehud Barak are considering launching action this autumn, before the US presidential election.

In an interview on Israeli television, Peres said: "It is clear to us we cannot do it on our own. We can only delay [Iran´s progress]. Thus it´s clear to us that we need to go together with America. There are questions of co-operation and timetables, but as severe as the danger is, at least this time we´re not alone."

He said he was confident that the US would take action, but added: "My estimate is that they will not do this before the elections, which are more than 80 days away."

Following the remarks, Netanyahu´s office openly attacked the president´s judgment, suggesting three previous occasions when it had been wrong. The first, according to an aide quoted in the Israeli media, was after the Oslo accords were signed in 1993, when Peres "thought there would be a new Middle East". The second was following Israel´s withdrawal from the Gaza Strip in 2005 when "he thought there would be peace … but in reality we got missiles".

The aide continued: "But Peres´s biggest mistake was in 1981 when he opposed [Israel´s] bombing of the Iraqi reactor. Luckily, prime minister Menachem Begin ignored him."

Peres later stood by his comments, saying: "I say what is in my heart with a loud and clear voice."

The president´s views echoed those of many former and current military, intelligence and political figures in Israel. US officials have also made repeated efforts to dissuade Netanyahu and Barak from unilateral action.

Earlier this week, the US chairman of the joint chiefs of staff, Martin Dempsey, said that Israel did not have the capacity to eliminate Iran´s nuclear programme. "I may not know about all of their capabilities. But I think it´s a fair characterisation to say that they could delay but not destroy Iran´s nuclear capabilities," he told reporters.

Some observers believe that the current frenzied speculation about a possible Israeli strike this autumn is aimed at forcing an unequivocal public statement in the coming weeks from President Barack Obama on America´s willingness to take military action against Iran, should diplomacy and sanctions fail.

According to an opinion poll by the Israel Democracy Institute and Tel Aviv University, 60% of Israeli Jews are against a strike on Iran without US co-operation. Eleven per cent strongly support unilateral action by Israel. (guardian.co.uk © Guardian News and Media Limited 2012 08/18/12)