SAS troops are tonight being sent to the Middle East to rescue Brits if needed amid rising tensions with Iran.
Britian's most elite fighting units are assembling in the wake of the assassination of Iran's most senior military chief General Qasem Soleimani.
He was killed in a drone attack ordered by Donald Trump near an airport in Baghdad on Friday.
It is understood around 50 members of the SAS will be joined by the Navy’s Special Boat Service and the Special Forces Support Group in Iraq to help any possible evacuation of Britons in the region, .
There are at least 1,400 military and UK government civilian personnel in Iraq as part of Operation Shader which is the UK mission to help train Iraqi and Kurdish forces defeat Islamic State.
Senior commanders fear British nationals could be targeted by Iranian-backed Shia militia groups based inside Iraq.
One senior UK defence source said: “Soleimani was an enemy combatant in a war zone who was deploying to oversee and orchestrate Iranian operations in a foreign country which would have resulted in the deaths of US soldiers, civilians and potentially British personnel as well.
“He knew the risks and took his chances as all troops do and he paid the price."
'PROTECT OUR SHIPS AND CITIZENS'
It came as Britain sent two warships to the Persian Gulf after America assassinated Iran's top general to "take all necessary steps to protect our ships and citizens" amid the tensions.
Defence Secretary Ben Wallace ordered the warships to the Strait of Hormuz off the coast of Iran as tensions are escalating in the region, according to .
And tomorrow, Boris Johnson will fly back to the UK from his holiday in Mustique as he faces the biggest test of his diplomacy in his premiership so far.
It comes as the Foreign Office escalated its warnings over travel to the Middle East.
Britain's navy will now accompany UK-flagged ships through the Strait of Hormuz to provide protection.
Defence minister Ben Wallace said he had ordered the warships HMS Montrose and HMS Defender to prepare to return to escort duties for all ships sailing under a British merchant flag.
"The government will take all necessary steps to protect our ships and citizens at this time," he said.
It comes after Iran today pinpointed 35 "key US targets" as it unfurled a red flag of revenge after its top general was assassinated in a US drone strike.
MOST READ IN WORLD NEWS
Hours later, rockets were fired near the US Embassy in Baghdad and at an airbase housing American troops, according to reports.
British nationals have now been advised not to travel to Iraq, apart from essential travel to its Kurdistan Region, and all but essential travel to Iran was warned against.
The Foreign Office said anyone in Iraq outside the Kurdistan Region should consider leaving immediately because the "uncertain" security situation "could deteriorate quickly".