A panel of Iranian lawmakers said Sunday that the inspections regime underpinning the country's nuclear deal with world powers represented a security threat, but the agreement should go ahead anyway.

The 15-member committee spent weeks reviewing the text of the July 14 agreement, known as the Joint Comprehensive Plan of Action (JCPOA), for what it said could be breaches of negotiators' "red lines".

The panel had largely been sidelined over its ability to influence the accord's fate although its report paves the way for a formal vote in parliament.

A law passed earlier this year gave final oversight of the nuclear deal to Iran's Supreme National Security Council (SNSC), rather than lawmakers, many of whom have railed against the agreement.

The SNSC is headed by President Hassan Rouhani, who came to power in 2013 after campaigning to end the international dispute and end sanctions imposed over Iran's nuclear programme.

In their report the lawmakers hit out at the decision to allow inspections of military sites, which supreme leader Ayatollah Ali Khamenei had appeared to rule out in a speech just weeks before the deal was sealed.

"It is evident that, based on the JCPOA, access to Iranian military sites has become possible," the panel said.

"The JCPOA has serious weaknesses in the security section. Unless there's a revision regarding the inspection of military, defence and security sites, it will cause problems for the country.

"Implementation of this inspection regime could lead to unprecedented information gathering and exposes to danger the security infrastructure, human, scientific, military and security resources of Iran."

The lawmakers, however, said the review made "the assumption that Iran's negotiating team had enjoyed the supreme leader's trust" during the talks that led to the deal and its passing would see sanctions lifted.

Khamenei has the last word on all policy matters in the Islamic republic as his authority trumps Rouhani and all politicians. His speeches often backed the negotiators but stopped short of endorsing the deal.

The panel further criticised the agreement with Britain, China, France, Russia and the United States plus Germany, saying Iran's obligations were "clear and explicit" whereas the West's obligations were not so.

"In case of any breach of commitments by the other side, Iran reserves the right to make any decision in its national interest," the report said, noting that the deal was a political agreement and not a binding treaty.

In particular the placing of restrictions on some aspects of Iran's nuclear activities for 15 years was "a serious shortcoming".

Under July's accord Iran will place limits on its nuclear programme for at least a decade in return for the lifting of all nuclear-related UN and international sanctions.

The inspections regime will be led by the International Atomic Energy Agency (IAEA).

Iran has always denied seeking to build an atomic weapon, insisting its nuclear programme is for peaceful energy production and medical purposes.