Iranian parliament speaker Ali Larijani
Iranian parliament speaker Ali LarijaniReuters

Iran's parliament speaker on Thursday said he expected a raucous debate in the Iranian legislature over approval of the nuclear deal which he said could unleash more drama than in the US Congress.

Ali Larijani, who backs the agreement reached with the West, declined to say whether he believed lawmakers in the Majlis (Iranian parliament - ed.) would, in the end, support the deal.

"I think maybe the drama in my country will be bigger than that in yours," Larijani told AFP reporters in New York, where he was attending a world conference of parliamentary speakers.

"There is one thing that I am sure of, and that is that there will be heated discussions and debate in the Iranian parliament."

Iranian supreme leader Ayatollah Ali Khamenei said earlier that parliament should vote on the agreement that provides for lifting sanctions on Iran in exchange for rolling back Iran's nuclear program.

On Wednesday, US President Barack Obama won enough backing in Congress to ensure that he can override with his veto power any vote rejecting the Iran deal.

Last month, the Majlis announced the makeup of a 15-member panel largely composed of conservative lawmakers to review the historic deal.

Larjani suggested that their findings in the coming weeks could set the tone for the parliament debate.

"We have to wait and see what kind of decision that committee will take and what the results will be," he said.

Serious faults in the deal

The speaker stressed that there were strong voices opposed to the nuclear deal in parliament.

"There are people who have found serious and major faults with the agreement", he said.

Among the grievances are the "snapback mechanism" that would allow the West to re-impose sanctions on Iran if it violates the deal and the strict surveillance regime put in place to ensure compliance.

"The sanctions can return," he said, but "for us this is not possible. We cannot go back to the situation that we were in."

"Once you remove the core of the Arak reactor, you cannot put it back. That is impossible," he said. The Arak reactor will be redesigned under the deal to address concerns about its enrichment capabilities.

"Overall it was a good deal because Iran also achieved some of its goals," he said.