Iran's envoy to the UK lashed out at critics who've described the new European financial mechanism with Iran, called INSTEX, a weak entity that's been created by only three European countries and not by all the 28 EU member states.

'Although it's not become operational yet, those who oppose the Iranian system have joined regional extremists and close allies of Trump in calling the INSTEX inefficient,' said Hamid Baeidinejad in a Twitter thread. 

'This shows their frustration,' he added. 

Baeidinejad explained that 'INSTEX (Instrument for Support of Trade Exchange) is a financial entity and not a European Commission institute that requires all states to become a member.'

'Three European countries (Germany, France, Britain) (E3), that have played fundamental role in the nuclear agreement, are its shareholders and founders,' he tweeted, saying 'all European Union has thrown its support behind it as written in a statement by Federica Mogherini, the EU's foreign policy chief.'

The Iranian ambassador also mentioned that 'other European states and later non-European countries, such as Russia and Chin can also join the mechanism.'

Head of the Iranian diplomatic mission in London went to detail that 'INSTEX will become operational in several phases: first, through mutual payment of vital commodities, medicine and medical devices to be later extended to all commercial dealings.'

Baeidinejad criticized that those who oppose the new financial channel, always repeat the word 'food' to revoke similarities with what the UN had put in place for Iraq in exchange for the Arab country's oil, also known as the Food-for-Oil Programme (OIP). 'However, these two are not similar at all,' he emphasised.

'The three European countries have guaranteed its power by sharing duties at hosting, managing and chairing the supervisory board,' wrote the Iranian envoy to Britain who referred to the British representative, saying 'he is the permanent under-secretary at the UK's Foreign Office.' 

He harshly criticized those who call the entity a mere accounting company, calling their comments 'philosophisation out of sheer anger.'

Germany, France and the UK foreign ministers announced the creation and registration of the Special Purpose Vehicle (SPV) for trade with Iran during a EU meeting in the Romanian capital, Bucharest at the end of January. 

The INSTEX headquarters is located in Paris, and former German Commerzbank manager, Per Fischer, has been chosen as it's head for a period of six months. Simon McDonald, Permanent Under-Secretary at the UK Foreign Office has also been designated to chair the supervisory board that is comprised of one representative from these three countries.

Other European states can also join the mechanism at a later stage. 

The INSTEX is supposed to act as a euro-based clearing house. At the first stage, it will be used to export pharmaceuticals, medical exports and agri-food stuffs. It could later be used to include other commercial items. 

The Iranian ambassador to the UK had earlier explained the delay in its implementation, saying 'it's the first time such a system is put in place and there is no previous experience about it.'

He has called the SPV an 'innovative move' by the E3, expressing hope it could turn into a practical mechanism to counter 'cruel US sanctions'.