British Prime Minister Boris Johnson
British Prime Minister Boris JohnsonReuters

In a new report calling for tougher relations with Tehran, UK lawmakers are urging Britain to spearhead an international effort to replace the 2015 Iran nuclear deal, AFP reports.

Parliament's watchdog foreign affairs committee said the deal -- known formally as the Joint Comprehensive Plan of Action (JCPOA) -- was now "a shell of an agreement" and "beyond repair".

"Despite good intentions, the JCPOA was an agreement built on weak foundations," committee chairman Tom Tugendhat said, noting its demise "seems to have been inevitable".

"The UK Government should work to broker a replacement to the JCPOA which also addresses regional security," he added, according to AFP.

"The voices of allies in the region and in Europe, and with the new US administration, need to come together to ensure a diplomatic option is available to those in Iran who are looking for a solution to decades of isolation," said Tugendhat.

US President Donald Trump withdrew from the Iran nuclear agreement in May of 2018 and reimposed sanctions on the Islamic Republic. Iran has gradually scaled back its compliance with the 2015 deal in response.

President-elect Joe Biden, however, has expressed a desire to rejoin the deal and recently told The New York Times that he would do so if Iran returned to compliance with it.

The European signatories to the deal - Britain, France and Germany - refused to follow the US and withdraw from the agreement and have been trying to save it. However, German Foreign Minister Heiko Maas earlier this month called for negotiations with Iran to conclude a broader nuclear deal.

The British committee's report also urges the British government to respond more effectively to Tehran's "wider destabilizing activities" in the region, according to AFP.

It recommends a range of measures including designating Iran's elite military force -- the Islamic Revolutionary Guard Corps (IRGC) -- a terrorist organization, as the United States did last year.

The MPs said the IRGC's "clear and enduring support for terrorists and non-state actors working to undermine stability in the region" would permit the move under UK law.