Feud: David Cameron with General Sir David Richards in Afghanistan in December 2010, who told him ‘being in the Combined Cadet Force at Eton’ did not qualify him to decide on military tactics

David Cameron’s leadership record is torn apart today by a former defence chief, Tory grandees and White House officials.

On Day Two of Lord Ashcroft’s explosive biography, the Prime Minister is accused of ‘doing an Iraq’ in Libya and rank incompetence over Syria.

Astonishingly, General Sir David Richards, says he had to tell Mr Cameron that ‘being in the Combined Cadet Force at Eton’ did not qualify him to decide the tactics of complex military operations.

At times, the PM was at war with the chief of the defence staff, who disagreed with him strongly on strategy.

In a further blow to his credibility on foreign affairs, former defence minister Nicholas Soames says the Royal Navy has been ‘stripped down to nothing’.

And former Tory chairman Michael Ancram says Libya is Mr Cameron’s ‘Iraq’ – with the country now more dangerous than when the PM decided to topple Colonel Gaddafi.

Day One of the biography’s serialisation in the Mail dominated the airwaves yesterday and was the most talked-about topic on Twitter around the world.

It also reignited the feud between Mr Cameron and Lord Ashcroft, a former Tory treasurer who has donated more than £8million to the party.

Day Two of the book, co-authored by the award-winning political journalist Isabel Oakeshott, uncovers:

The decadent parties of the Chipping Norton set, of which the Camerons are leading lights; the set is dubbed ‘Chipping Snorton’ because Class A drugs circulated;

How Mr Cameron’s brother Alex went on holiday with Rebekah and Charlie Brooks during their phone hacking trial;

The first ever picture of the Prime Minister riding to hounds on horseback;

His direct intervention to complain about the prosecution of a huntsman – the case was subsequently dropped;

How the PM came close to sacking George Osborne in a row over his meetings with a Russian billionaire;

His absence from the meeting where his shadow cabinet decided to abandon support for grammar schools but stick with the policy for ‘cosmetic’ reasons.

Criticism: Former defence minister Nicholas Soames (left) says the Royal Navy has been ‘stripped down to nothing’, and former Tory chairman Michael Ancram (right) says Libya is Mr Cameron’s ‘Iraq’

More revelations: On Day Two of Lord Ashcroft’s (left) explosive biography, the Prime Minister (right) is accused of ‘doing an Iraq’ in Libya and rank incompetence over Syria

The savage critique of Mr Cameron’s foreign policy skills comes at the worst possible time for Number 10 because it is planning to ask MPs to vote for military action against Islamic State in Syria in weeks.

The book reveals astonishment inside the White House at the Government’s ‘incompetence’ over the vote in 2013 to take military action against Syrian despot Bashar al-Assad.

The vote was lost after the Prime Minister wrongly assumed he had Labour’s support in the bag’.

Writer: The book is co-authored by the award-winning political journalist Isabel Oakeshott

One Obama administration insider says: ‘It was one of those astonishing displays of incompetence that sort of leaves you wondering about how, you know, have we all got this far?’

The White House considered they had been ‘****ed over’ on both Libya and Syria, senior sources tell Lord Ashcroft and Miss Oakeshott.

During repeated clashes over foreign policy, Sir David – now Baron Richards – had to point out that military interventions were more complicated than supporting the ‘good guys’ versus the ‘bad guys’.

A former member of the National Security Council backs that assessment, saying of the PM: ‘His instinct is to support the underdog, without analysing what that really means.’

The authors, who interviewed a string of senior White House and US military officials during visits to America, also claim the Prime Minister had a ‘derring do’ plan to take out President Assad.

Sources say the commando-type operations were simply implausible and ‘would have been getting everybody into deeper waters’.

On Libya, where Mr Cameron led the charge in 2011 to bring down Gaddafi, Ancram tells the authors the intervention played into the hands of terrorists.

Libya is now a hotbed for Islamist extremism and is also used as a launch pad by people smugglers sending migrants to Western Europe.

Surprise: The explosive biography reveals astonishment inside the White House at the Government’s ‘incompetence’ over the vote in 2013 to take military action against Syrian despot Bashar al-Assad (pictured)

‘We now have a country which is ungovernable ... with vast amounts of weapons from Gaddafi’s arsenal moved south of the border, arming Boko Haram [extremists in Nigeria],’ Ancram says.

They’re actually more of a threat to us than Gaddafi was at the time Michael Ancram, former Tory chairman, speaking about Libya

‘They’re actually more of a threat to us than Gaddafi was at the time.’

Devastatingly, in a comparison with Tony Blair, he accuses Mr Cameron of ‘doing an Iraq’.

‘To claim it was only about protecting citizens in Benghazi, so we’re going to bomb the living daylights out of Gaddafi in the south and everyone else, just simply doesn’t hold water,’ he says.

‘It makes me think that, rather like Blair, he was determined to change the regime.’

Baron Richards, who left the military in 2013, says: ‘We never really analysed things properly.

Under fire: In a comparison with Tony Blair (right), Mr Cameron (left) is devastatingly accused of 'doing an Iraq'

‘Our instinct is knee-jerk support for the underdog, without doing the analysis that would necessarily legitimise that course of action.’

Our instinct is knee-jerk support for the underdog, without doing the analysis that would necessarily legitimise that course of action General Sir David Richards

Day One of the serialisation dominated the day’s events at Westminster yesterday, with allies of Mr Cameron claiming Lord Ashcroft was ‘out for revenge’.

The Prime Minister’s official spokesman refused to ‘dignify’ the book with any comment.

There was also widespread speculation over the identity of the MP who told the authors that, during an initiation ceremony for a debauched dining society at Oxford University, the PM had ‘inserted a private part of his anatomy’ into the mouth of a dead pig.

Friends of Mr Cameron dismissed the suggestion as ‘total c***’, though there was no official denial.

The initial extracts also contained on-the-record claims of how Mr Cameron smoked cannabis at university and that cocaine was in circulation at a dinner party at his west London home.

No response: The official spokesman for the Prime Minister (pictured last night at 10 Downing Street making a speech to mark a successful summer of cricket) refused to ‘dignify’ the book with any comment

Number 10 pointed to Lord Ashcroft’s admission that he had personal ‘beef’ with the PM after the 2010 election.

If this was just a revenge job then Lord Ashcroft and I could have published it before the election Isabel Oakeshott, co-author

The billionaire former peer said that Mr Cameron reneged on a promise to give him a significant role – triggering their split.

The PM’s spokesman said of Lord Ashcroft: ‘The author has set out his reason for writing it.’

Miss Oakeshott, who was political editor at the Sunday Times, hit back yesterday: ‘If this was just a revenge job then Lord Ashcroft and I could have published it before the election.