A majority of deputies in the Majlis on Tuesday gave their final approval to a law that would oblige the government to "stop voluntary and non-legally binding measures and implement its scientific, research and executive programmes" in the nuclear field if the Iranian case is taken up in New York.
The International Atomic Energy Agency's (IAEA) 35-nation board of governors was to discuss Iran on Thursday.
Iranian officials have threatened retaliation if this happens, and the move by parliament, subject to the approval of the Guardians Council, the country's legislative watchdog, is seen as a means for Iran to reinforce such warnings.
The text does not refer to specific reprisals, but Iran has said it could refuse to adhere to the additional protocol of the nuclear Non-Proliferation Treaty, which gives increased inspection powers to the IAEA.
The protocol, signed by the previous reformist government but not ratified by parliament, is seen as crucial to an IAEA investigation into allegations that Iran is using an atomic energy drive as a cover for weapons development.
Officials have threatened to end a freeze of uranium enrichment, a process used to make reactor fuel but which can also make the explosive core of a nuclear weapon.
Resumption of talks
Meanwhile, Britain, France, Germany and Russia have set a provisional date in December to meet Iran in a move aimed at breaking the deadlock over Tehran's disputed nuclear programme, diplomats said on Tuesday.
The parliament's move is part of
Iran's retaliatory threat
"The date is 6 December. There is no agreement yet on the venue," said a European diplomat, who asked to remain anonymous due to the sensitivity of the issue.
New talks would be the next step after the US and the EU-3, Britain, France and Germany, put off calling this week on the UN nuclear watchdog to send the Iranian case to the UN Security Council, to give Russia time to get Tehran to agree to a compromise.
The diplomat said the idea would be to "talk about [resuming] talks" between Iran and the trio of European Union negotiators on guaranteeing Tehran will not make nuclear weapons.
The European diplomat said it was not clear whether the EU-3, Russia and Iran would all sit down together on 6 December at the level of political directors, or if "they would meet in mixed forms".