Lord Stuart Polak has claimed the UK’s decision to abstain over an American led proposal to extend the United Nations arms embargo against Iran was “an error of judgement” that left Washington  “exposed and lonely”.

Speaking in the  House of Lords, the Conservative life peer sought clarification from Minister of State Lord Ahmad of Wimbledon on how “are we going to stop the spread of arms to the terror-supporting Iran?”

In August the US had suffered a humiliating defeat at the United Nations as its proposal to extend an arms embargo against Iran won support from only the Dominican Republic at the Security Council.

While Russia and China voted against the proposal, the UK was among the other council members who abstained.  The UN arms embargo on Iran is due to expire on October 18.

Speaking on Thursday, the Conservative Friends of Israel Honorary President said: “Our abstention on extending the UN arms embargo was an error of judgement.

“China and Russia were always going to veto to support Iran, three countries who are not known for honouring gentlemen’s agreements.

“We should have voted with the US to make it clear that  we oppose Iran accessing arms thorough the legitimacy of the UN.

“Sadly we chose to leave the US exposed and lonely when in truth we agree with them.

“There are ten days before the expiry date  – can  I ask my Noble Lord to take a lead and do what is right?

“If not, can he explain our policy going forward?  How are we going to stop the spread of arms to the terror supporting Iran?”

Responding Lord Ahmad said:  “I share with my noble friend the intent, which is to stop the destabilising influence of Iran.

“The UK abstained because the resolution could not attract the support of the council and therefore did not represent a basis for achieving consensus.

“He asked about the way forward, we are addressing systematic Iranian non-compliance and Iran must engage seriously with our concerns.

“We remain committed to countering Iranian proliferation to non-state actors.

“The EU’s  arms embargo and UN’s  ballistic  missile restrictions will remain in place.”

Baroness Deech referred to the US call for “snapback sanctions” against Iran involving the arms trade. “Is the Government going to comply with these?,” asked the crossbench peer. “And how otherwise will it ensure Iran’s nuclear ambitions are blocked?”

Lord Ahmad said it was important that we keep the Joint Comprehensive Plan of Action (JCPOA) – the agreement  intended to prevent Iran from developing nuclear weapons while granting it an internationally monitored civilian nuclear power programme – which he said was an “imperfect agreement” but one we “must ensure they adhere to.”