by Ewen MacAskill
US to adopt much tougher line over Iran's nuclear ambitions
Israel to freeze construction of settlements on West Bank
France and Russia offer to host Middle East peace conference
Key to bringing Israel on board is a promise by the US to adopt a much tougher line with Iran over its alleged nuclear weapons programme. The US, along with Britain and France, is planning to push the United Nations security council to expand sanctions to include Iran's oil and gas industry, a move that could cripple its economy.
In return, the Israeli government will be expected to agree to a partial freeze on the construction of settlements in the Middle East. In the words of one official close to the negotiations: "The message is: Iran is an existential threat to Israel; settlements are not."
Details of the breakthrough deal will be hammered out tomorrow in London, where the Israeli prime minister, Binyamin Netanyahu, is due to hold talks with the US special envoy, George Mitchell. Netanyahu met Gordon Brown today in Downing Street, where the two discussed both settlements and the Iranian nuclear programme.
Although the negotiations are being held in private, they have reached such an advanced stage that both France and Russia have approached the US offering to host a peace conference.
Obama has pencilled in the announcement of his breakthrough for either a meeting of world leaders at the UN general assembly in New York in the week beginning 23 September or the G20 summit in Pittsburgh on 24-25 September.