David Cameron failed to take military action in Syria that could have stopped the rise of Islamic State (IS) because he lacked the "balls", a former head of the armed forces has said in an explosive new biography of the prime minister.
In a scathing analysis of Cameron's approach, General Lord Richards of Herstmonceux said it too often seemed "more about the Notting Hill liberal agenda rather than statecraft".
Lord Richards, who was chief of the defence staff from October 2010 to July 2013, said this in an interview for a biography of Cameron by Sir Anthony Seldon, being serialised in the Mail on Sunday from today.
Lord Richards (right) said Cameron's approach seemed 'more about the Notting Hill liberal agenda rather than statecraft'
He revealed last year that the Prime Minister had in 2012 rejected a "coherent military strategy" to take on the regime of Syrian president Bashar al Assad which would in his view have seen the Islamic extremists "squeezed out of existence".
In the book - titled Cameron at 10: The Inside Story 2010-2015 - Lord Richards is quoted as saying: "If they had the balls they would have gone through with it... if they'd done what I'd argued, they wouldn't be where they are with ISIS.
"In Ukraine, as in Syria and Libya, there is a clear lack of strategy and statecraft.
"The problem is the inability to think things through. Too often it seems to be more about the Notting Hill liberal agenda rather than statecraft."
The books also claimed the then-head of MI6, Sir John Sawers, told Cameron to his face that the 2011 military intervention in Libya was purely for "humanitarian reasons" rather than being in the "national interest", emphasising the difference between the two.