Alarmed by mounting US pressure and United Nations sanctions, officials close to Ayatollah Ali Khamenei favour the appointment of a more moderate team for international negotiations on the supervision of its nuclear facilities.
The move would be a snub to the bellicose president, Mahmoud Ahmadinejad, whose threats to destroy Israel have left Iran increasingly isolated and facing a serious economic downturn.
Tehran sources said the impetus for a policy switch was coming from Khamenei, who has ultimate power over Iran's foreign policy, security and armed forces.
Khamenei is said to believe that Washington's aim is not only to halt Iran's nuclear programme but to overthrow the regime.
He also considers the national interest is being undermined by an inexperienced president whose rhetoric is unnecessarily inflammatory.
Under proposals now being debated, an international group made up of the permanent five members of the UN security council, plus Germany or a nuclear power such as India, would oversee and monitor Iran's nuclear programme.
Washington may judge this too little, too late. But European negotiators would be expected to regard such a move as a significant step towards reopening talks about the programme. Tehran insists it is for civilian power but the West believes it is aimed at creating nuclear weapons
Last month the security council imposed sanctions on Iran. It set a 60-day deadline for Tehran to suspend nuclear activity or face further sanctions. Washington's tough stance and claims that Israel has drawn up plans for a nuclear strike against Iran's uranium enrichment facilities have alarmed Tehran's conservative leadership.
Ahmadinejad tried to dismiss such fears on a trip to Central America last week. Referring to a Sunday Times report about preparations for possible Israeli airstrikes with nuclear-tipped "bunker busters", he said: "I don't think they would ever dare to attack us, neither them nor their masters. They won't do such a stupid thing."
He is due to appear before parliament today to present his annual budget. But the poor showing of his allies in December's local elections has also emboldened his parliamentary critics.
In a sign that his power is waning, Iranian MPs have criticised Ahmadinejad for his handling of the nuclear negotiations and the country's mounting economic crisis.
Sa'id Leylaz, a leading economist, said: "The future of the nation has never been this dark, both economically and politically."
Iranians face rocketing prices for food and housing and sharply increased unemployment, estimated at 30%.
"Ahmadinejad is under extreme pressures from his own supporters to change policies," said Leylaz. Sources in Tehran say Ahmadinejad could be vulnerable, as Khamenei has clearly signalled his displeasure and has the power to dismiss him.
Khamenei rarely speaks in public, but the Islamic Republic, a newspaper he owns, launched a strong attack on Ahmadinejad's "personalisation" of the nuclear issue. In an editorial, it stated: "Our advice to the president is to speak about the nuclear issue only during important national occasions, stop provoking aggressive powers like the United States and concentrate more on the daily needs of the people, those who voted for you on your promises."
Ahmadinejad's weakness is being exploited by Ali Akhbar Hashemi Rafsanjani, a conservative pragmatist and former president who was defeated by him in elections in 2005.
According to the Tehran sources, one of the possible members of a new Iranian negotiating team would be Mohammad Moussavian, a former senior nuclear negotiator and an ally of Rafsanjani.
Last week Moussavian accused Ahmadinejad of misleading the country about the dangers it faced as a result of UN penalties.
Additional reporting: Safa Haeri