A ROYAL Navy nuclear-powered submarine armed with Tomahawk cruise missiles is in position to strike Iran if tensions give way to war in the Middle East.

Despite desperate attempts to de-escalate the stand-off between the US and Iran, Top Brass are working furiously to ensure Britain is ready to back America militarily if asked.

9 A Royal Navy attack submarine armed with Tomahawk cruise missiles is in position to strike Iran Credit: EPA

9 Soleimani was wiped out after intelligence was received that his forces were about to launch kidnap raids on American citizens and diplomats in the Middle East Credit: AP:Associated Press

Elite operatives from the SAS and SBS were also heading to Iraq braced for rescue missions, it was reported last night.

The death of Iranian military commander Qasem Soleimani in a US drone strike on Thursday has sparked fears of a third Gulf War.

In the capital Tehran yesterday, Iran’s president issued a chilling warning that the US made a “grave mistake” and warned it will face consequences for years to come.

Soleimani was wiped out after intelligence was received that his forces were about to launch kidnap raids on American citizens and ­diplomats in the Middle East.

US President Donald Trump also claimed Soleimani had planned bloody attacks in London.

While the world held its breath for Iran’s next move, senior defence sources revealed that an Astute class hunter-killer sub was sat silently in range of Iranian targets.

UK'S DEADLY MISSILES ALREADY IN RAGE OF IRAN

An insider said: “There will be no first strike, but every precaution is being made, depending on how Iran reacts to the death of Soleimani.

“If things unravel quickly, the UK will always stand shoulder-to-shoulder with the US. The hunter-killers are the most advanced submarines in the Royal Navy. They are a deadly asset and there is one well within range of Iran.”

The Navy keeps an attack sub in the region at all times. The crew would just need to manoeuvre into a “firing pocket” and unleash the missiles. The 20ft Tomahawk missile carries a 1,000lb high-explosive warhead with the power to destroy a building. It has a range of more than 1,550 miles, travels at more than 550mph and has a GPS guidance system allowing it to switch targets mid-flight.

Tomahawk land-attack cruise missiles were last fired by the Navy in 2011 against Gaddafi’s military facilities in Libya.

And they were used by the Navy in Iraq in 2003 and Afghanistan in 2001.

9 US President Donald Trump also claimed Soleimani had planned bloody attacks in London Credit: Alamy Live News

9 It has been reported PM Boris Johnson was not warned about the strike Credit: Splash News

9 The burning wreckage of Soleimani's convoy near Baghdad Airport Credit: Iraq Security Media Cell

They are often first choice for an initial strike before a major offensive. US “monster” sub-USS Florida is also certain to be in reach of Iran after leaving Gibraltar days ago. Also nuclear-powered, it can carry 154 cruise missiles.

Soleimani, Iran’s top military leader, was hailed as a hero in his country. The officer, 62, was the second most powerful ­figure in Iran — responsible for its sinister operations abroad.

For 21 years, he commanded the elite Quds force, part of the Iranian Revolutionary Guard, and reported directly to the Supreme leader ­Ayatollah Khamenei.

He was behind Syria’s civil war, attacks on US and UK troops, the rise of pro-Iranian militia in Iraq, and bolstered terror groups in the region. But his convoy was reduced to a smouldering heap in Baghdad.

In a visit to the notorious ­general’s house on Saturday, one of Soleimani’s daughters asked President Hassan Rouhani for revenge.

He promised her that “everyone will take revenge” and added: “The Americans did not realise what a grave mistake they have made.

CHANTS OF 'DEATH TO AMERICA'

“They will suffer the consequences of such criminal measure not only today, but also throughout the years to come.” A vast crowd gathered yesterday in Baghdad for a funeral procession, marking the first of days of mourning for Soleimani. They were also there to mourn Iraqi paramilitary chief Abu Mahdi al-Muhandis, killed in the strike too.

Outraged Iraqis waved militia flags and chanted “Death to America”.

The US said it had deployed 3,000 more troops to the Middle East to respond to any backlash.

The UK has 400 in the region plus Special Forces in Syria — but it was claimed PM Boris Johnson was not warned about the strike.

Up to 50 operatives from the SAS and SBS are also being drafted in, the Sunday Mirror reported.

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Mr Trump said: “The United States military executed a flawless precision strike that killed the number one terrorist anywhere in the world, Qasem Soleimani.”

He said the commander was “plotting imminent and sinister attacks on Americans” and added: “Soleimani made the death of ­innocent people his sick passion — contributing to terrorist plots as far away as New Delhi and London.”

Royal Navy warships will shadow commercial vessels through the perilous Strait of Hormuz, the Defence Secretary announced last night.

UK troops have also been ordered to abandon their training of Iraqi forces and switch to securing the British embassy in Baghdad, the Sunday Times reported.

9 Weeping Iraqis carry coffins during funeral procession yesterday of Iraq paramilitary chief Abu Mahdi al-Muhandis and Iranian commander Qasem Soleimani Credit: AFP or licensors

9 Outraged Iraqis waved militia flags and chanted 'Death to America' Credit: AFP or licensors

9 Qasem Soleimani was identified by the ring on his hand Credit: PA:Press Association

9 An angry mob burns the American flag in Tehran Credit: Reuters

Iran's leader Rouhani was close with the slain general Credit: AP:Associated Press

Suspicion and hate over the years By Graeme Culliford IRAN’S relationship with Britain has been filled with hatred and mutual suspicion since 1979. That was when the country’s UK-backed Shah was overthrown by the Islamic revolution. In 1980 an SAS team stormed the Iranian Embassy in London to save 22 hostages. One hostage died in the crossfire. The five gunmen killed were from a terrorist group opposed to Ayatollah Khomeini’s regime. In 1989 Khomeini declared a “fatwa” — a murder order — against author Salman Rushdie. In 2004 eight UK sailors were held three days after their ship reportedly entered Iran’s waters. In 2007 15 Navy personnel were seized by the Iranian Revolutionary Guard for 13 days. In 2016 UK-Iranian national Nazanin Zaghari-Ratcliffe, 42, was arrested on trumped-up charges. She is still in prison. The following year a cyber-attack on Parliament was blamed on Iran. And last year Marines seized an Iranian-owned oil tanker heading for Syria.

Moment Iranian general Qasem Soleimani is ‘torn to shreds’ by US Reaper drone moments after he landed in Baghdad