Rishi Sunak rejects calls to proscribe Iran's Revolutionary Guard as a terror group - as Israel's military chief insists the country WILL respond to missile strike despite pleas from world leaders not to retaliate

Rishi Sunak has rejected calls to proscribe Iran's Islamic Revolutionary Guard Corps (IRGC) as a terror group amid fears it could destroy relations with Tehran at a crucial time, sources have claimed.

The Prime Minister is under mounting pressure from both Labour and Tory MPs - including former Home Secretary Suella Braverman - to ban the IRGC after Iran's unprecedented 350-missile attack against Israel on the weekend.

Israel has vowed that the Iranian strike 'will be met with a response' over the weekend - despite world leaders being united in their view that Israel should 'take the win' and not retaliate. 

Mr Sunak on Monday condemned Tehran as a 'despotic regime' but government sources claimed proscribing the IRCG would put Britain 'at a disadvantage'. 

Foreign Secretary Lord Cameron has said that Britain's diplomatic relations with Iran, including a British embassy, allow the UK to 'deliver a direct message to the Iranians'. 

The Prime Minister's spokesman said the UK's presence in Iran is 'one of our most effective channels for avoiding escalation' and enables 'robust messages' to be delivered to the regime.

A senior government source told The Times: 'It is better to keep talking to them directly rather than go through proxies. Proscribing the IRGC would put us at a disadvantage. We keep all these things under review but they have been heavily sanctioned already.' 

Proscribing Iran's Islamic Revolutionary Guard Corps has divided the Government. While Mr Sunak, Mr Cameron and Home Secretary James Cleverly have so far resisted calls to ban the group, Security Minister Tom Tugendhat would favour action to be taken.

Mr Sunak said on Monday that he would tell Israeli Prime Minister Benjamin Netanyahu to 'show restraint' as the IDF decides how it will retaliate.

'I will also shortly be speaking to Prime Minister Netanyahu to express our solidarity with Israel in the face of this attack, and to discuss how we can prevent further escalation,' Mr Sunak told MPs in the Commons on monday.

Mr Sunak said: 'With this attack Iran has once again shown its true colours. They are intent on sowing chaos... on further destabilising the Middle East. We're working urgently with our allies to de-escalate the situation and prevent further bloodshed.

'We want to see calmer heads prevail and we're directing all our diplomatic efforts to that end.'

His comments echo those of US President Joe Biden and other western allies including France.

Lord Cameron, of Chipping Norton, agreed on Monday that Israel should 'take the win' after 99 per cent of the missiles fired by Iran were intercepted. The Foreign Secretary, who is expected to travel to Israel shortly for a pre-arranged trip, will tell Netanyahu not to retaliate.

But Israel's military chief said his country will respond to Iran's missile strike over the weekend.

Lt Gen Herzi Halevi said that Israel is still considering its steps. But he said the Iranian strike of missiles and attack drones 'will be met with a response'. Lt Gen Halevi spoke during a visit to the Nevatim airbase, which Israel says suffered light damage in the Iranian attack.

Mr Netanyahu has been meeting with top officials to discuss a possible response.

The Iranian attack on Saturday marked the first time Iran has launched a direct military assault on Israel, despite decades of enmity dating back to the country's 1979 Islamic Revolution.

The attack happened less than two weeks after a suspected Israeli strike in Syria that killed two Iranian generals in an Iranian consular building.

The Israeli military says that 99 per cent of the drones and missiles launched by Iran were intercepted, with the help of other countries including the United States, the UK and France. 

Mr Sunak said RAF jets shot down 'a number' of drones during what was the biggest air-to-air battle involving the UK since the Falklands in 1982.

Despite the reported interceptions, Iran has called the attack a success. In Washington, US National Security Council spokesman John Kirby declined to say whether the US had been or expects to be briefed on any Israeli response plans.

'We will let the Israelis speak to that,' he told reporters. We are not involved in their decision-making process about a potential response.'

The IRGC - which carried out the attack - was founded as a custodian of Iran's 1979 revolution but has since grown into a major, political and economic force for the country.

Rumblings about the IRGC becoming a terrorist organisation in the UK have been ongoing for months now.

Proscription would make it illegal to be a member of or support the group in the UK - putting it on the same level as Islamic State and al-Qaeda. The Hamas terrorist group which massacred 1,200 Israelis on October 7 have also been proscribed in the UK.

Senior Conservative figures have led calls for the UK to ban the IRCG as a terror group following the country's attack on Israel. The US prescribed the Iranian state's security body as a terrorist organisation in 2019

Tory former cabinet ministers Sir Iain Duncan Smith and Ms Braverman urged Mr Sunak to take the step following Iran's missile and drone barrage over Israeli airspace, which the UK and other allies joined efforts to thwart.

Sir Iain asked the Prime Minister to consider proscribing the IRGC after he speaks to the UK's allies about joint next steps.

The move would see the organisation added to a list of banned groups, which includes Islamists and far-right terrorists.

Ms Braverman meanwhile suggested the move would 'put the UK's national security first'.

Sir Iain told the Commons: 'All roads lead back to Tehran when it comes to the terrible violence and the wars that take place in the Middle East.

'And every country, not just Israel, other Arab countries fear what Tehran is doing in their countries as well, I think we forget about it.

'We know that they are committing murder at home, they have executed thousands of protesters whilst this war ... has been taking place.

'With all of that known, could I please ask him, when he sits down with our international colleagues and looks for other things to take place with regards to restricting Iran, please, please could he now consider proscribing the Islamic Revolutionary Guard Corps - and to do it in a way that will make sure they can no longer foment extremism here in the United Kingdom as well?'

The Prime Minister replied: 'We are urgently working with our allies to see what steps we can take together in a co-ordinated fashion to deter and condemn what Iran is doing.'

In an earlier reply to Labour leader Sir Keir Starmer, Mr Sunak suggested any steps to further limit the IRGC's reach would be taken in concert with the UK's allies.

He told the Commons: 'Yesterday at the G7 we agreed to work together on further measures to counter the Iranian regime and its proxies.

'It was agreed that we should co-ordinate those actions and that work is now under way, and obviously at the appropriate time either I or ministers will update the House.'

Former home secretary Ms Braverman meanwhile told MPs about her recent visit to Israel's northern border, where 'Iran-backed Hezbollah has fired over 4,000 rockets into northern Israel, displacing over 150,000 Israeli civilians'.

She added: 'We have known for years that the Islamic Revolutionary Guard Corps is the world's chief sponsor of terrorism, funding and promoting terrorist plots, radicalisation and hostage-taking both in the Middle East and at home.

'We have proscribed Hezbollah, we have proscribed Hamas, Prime Minister, why don't we put the UK's national security first by now proscribing the IRGC?'

Mr Sunak replied: '(Ms Braverman) knows that we don't comment on any potential proscription decisions but of course we recognise the threat from Iran and have taken measures to counter it at home and around the world.'

Bob Blackman, Conservative MP for Harrow East, said: 'The proscription of the IRGC; the removal of the embassy here and return of all those officials to Iran; our officials returning to the United Kingdom; and the harshest possible sanctions against the regime in Iran; are the fundamentals that are required.'

Conservative former minister David Jones also backed proscribing the IRGC, adding: 'It's actually the case that IRGC officials can be seen dining out in restaurants in west London quite regularly.'

Elsewhere, the Prime Minister insisted the UK's position on selling arms to Israel remained unchanged.

Labour MP Zarah Sultana (Coventry South) asked Mr Sunak about reports that Alicia Kearns, Conservative chairwoman of the Foreign Affairs Select Committee, believes the Government has received advice that Israel is flouting the law but has refused to confirm this.

The Prime Minister replied: 'As the Foreign Secretary (Lord Cameron) confirmed last week, the UK position on export licences is unchanged, and following the latest assessment is in line with our legal advice.

'We will keep that position under review and act in accordance with advice. I would also point out to her that actually most like-minded countries have not suspended their existing arms export licences to Israel.'

MailOnline contacted No 10 for comment.