SAS commandos were poised to destroy Syria's chemical weapons arsenal
The then-prime minister reportedly aborted the 2013 raid after cabinet discussions because he feared up to half the crack squad of around 100 troops could have been killed in the secret attack.
But the SAS mission could be revived four years on after the horrific Sarin attack which killed 80 men, women and children.
The head of Britain's special forces has briefed Theresa May's crisis committee Cobra and sources told the Mirror they could still be sent in to do the job after this week's chemical weapons massacre.
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David Cameron aborted the mission over safety fears
MI6 has also asked its operatives in Syria to try to gather samples from the largely opposition-held Idlib province where Assad's deadly chemical weapons attack took place.
Former MP Mr Cameron wanted Britain to launch air strikes on Syria in 2013 but lost a Commons vote authorising the use of military force in Syria.
Ed Miliband, Labour leader at the time, looked set to support the government but backed down after realising he did not have the support of his party.
Ed Miliband voted against British military action against Syria in 2013
This decision resulted in a defeat for the government after 31 Tory MPs rebelled.
Barack Obama’s White House put a US military attack on Syria on hold the next day after failing to get the support of Congress, despite Assad’s use of chemical weapons being a flagrant breach of what he had called a ‘red line’.
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The secret SAS mission could be arranged by top brass Celebrities and Politicians React to Trump's Missile Attack on Syria Fri, April 7, 2017
Following news of the attack, celebrities and politicians expressed their thoughts on social media
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Trump ordered a massive military strike against a Syria
The West’s ability to protect civilians and influence the war has been severely limited ever since.
ISIS seized large swathes of territory in the conflict-ravaged country a year later and Russia joined the war in 2015, exploiting the vacuum left by the US and Europe.