Iranian parliamentarians gathered signatures on Tuesday to demand that the government carry on enriching uranium to levels of 20 percent, a move that could complicate nuclear talks between Iran and world powers in Geneva this week.
Iran is to meet six world powers on Wednesday for a new round of negotiations after the two sides came close to agreeing an interim deal during talks earlier this month.
Those talks were stalled by the elimination of an explicit recognition of Iran's right to enrich uranium in the draft text and demands from the French delegation that the Arak heavy-water reactor - which is feared could be used to make bomb-grade plutonium - be shut down.
Iranian President Hassan Rouhani has repeatedly said Iran will never give up its right to enrich uranium for peaceful purposes, a message Iran's parliament, dominated by conservatives, appears to want to hold him to.
"On the eve of the Geneva talks, we plan to approve such a proposal in parliament. Based on that the government is obliged to protect the nuclear rights of Iran in the forthcoming negotiations," Mehr news agency quoted member of parliament Fatemeh Alia as saying.
Another MP, Mehdi Mousavinejad, said the measure would require the government to maintain enrichment of uranium to 20 percent, complete the nuclear fuel cycle and finish construction of the Arak heavy water reactor.
While it has limited powers in the Islamic Republic's complex political system, parliament would likely vote on any nuclear deal. However, it would be very unlikely to go against the wishes of Supreme Leader Ayatollah Ali Khamenei.
Rouhani's approach to the talks, which he says is the best way to get sanctions hobbling Iran's oil-based economy lifted, has Khamenei's backing. Rouhani succeeded hardliner Mahmoud Ahmadinejad in August.
Iranian political figures have lined up to criticize France for jeopardizing the chance to reach a nuclear agreement, after Foreign Minister Laurent Fabius warned against accepting "a fool's game".
On Monday, French President Francois Hollande set out a tough stance against Iran during a visit to Israel, saying he would not give way on nuclear proliferation.
His remarks came in for criticism on Tuesday from an Iranian parliamentary official.
"We advise the president of France to comment on the basis of facts, not assumptions, and beyond that, not to be the executor of the Zionist regime's (Israel's) plan," Alaeddin Boroujerdi, the head of the assembly's national security and foreign affairs committee told its official news agency.
Iranian Defense Minister Hossein Dehqan denied accusations by an exiled opposition group that Tehran was building a secret underground site to develop a nuclear arsenal. He accused the group and Israeli Prime Minister Benjamin Netanyahu of spreading false information to undermine the nuclear talks.
(Reporting by Marcus George and Isabel Coles; Editing by Jon Hemming and Janet Lawrence)