Tehran’s approach to talks on its nuclear programme in Vienna has become so uncompromising according to Israel’s lead diplomat on Iran, Joshua Zarka, that they “have reached the last stretch of diplomacy”. Israeli officials said they were hopeful that the US and European nations would agree to put an emergency motion to the board of the International Atomic Energy Agency (IAEA) stating that Iran was in breach of its obligations under the non-proliferation treaty (NPT) and the 2015 nuclear deal. Such a motion, planned for this month, would be the start of a wider process to try to force Iran to change its behaviour on the nuclear question. Israel has long sought to push its allies away from negotiations with its arch-enemy, saying such talks could be fruitless and that Iran would still seek to covertly advance its weapons programme unless forced to abandon it. Zarka was speaking as the director general of the IAEA, Rafael Grossi, said advances made by Iran since the 2015 nuclear deal’s collapse meant there would have to be changes to the original agreement. “The reality is that we are dealing with a very different Iran,” he said. “2022 is so different from 2015 that there will have to be adjustments that take into consideration these new realities so our inspectors can inspect whatever the countries agree at the political table. “There’s no other country other than those making nuclear weapons reaching those high levels” of uranium enrichment, Grossi said of Iran. “I’ve said many times that this doesn’t mean that Iran has a nuclear weapon. But it does mean that this level of enrichment is one that requires an intense verification effort.” Grossi said the restrictions faced by his inspectors in Iran threatened to give the world only a “very blurred image” of Tehran’s programme. “If the international community through us, through the IAEA, is not seeing clearly how many centrifuges or what is the capacity that they may have … what you have is a very blurred image,” he said. “It will give you the illusion of the real image. But not the real image. This is why this is so important.” Russia in particular has, according to Israeli officials, been pressing Iran to allow UN inspectors to operate more freely, and the first crunch point may come before the end of this month at the IAEA board if Grossi declares the inspectors have still not been given the access they need. Zarka said he would not be drawn on the military options available to Israel, which he was not responsible for. But Israel has repeatedly said it would not allow Iran to acquire a nuclear weapons capability. Israel believes it is winning the argument with British and US officials that the new Iranian regime – elected in June and answerable to the supreme leader, Ali Khamenei – has decided it does not need to go back to the joint comprehensive plan of action agreed in 2015, but will instead try to buy time to build its nuclear capabilities. The accumulation of steps taken by Iran means, Israel believes, that the country is weeks away from the point when it will have uranium enriched up to 90%, a position described as the break-out moment in the 2015 nuclear deal. Israel has never admitted to its role in the previous strikes on Iran, including the assassination of the head of Iran’s nuclear programme, Mohsen Fakhrizadeh. The Iranian ambassador to London, Mohsen Baharvand, told a briefing last week it was reasonable for Iran to ask for guarantees, along the lines of an international treaty, that the US would remain in the agreement permanently, and not walk out – as Donald Trump did, with Israel’s support.