'A study in privilege': Iain Macwhirter on David Cameron's memoir

Collins, £25

HOW do you review a book that has already been filleted by extracts in the press, every morsel of news extracted? We all know about David Cameron's pot smoking at Eton. We know how he felt about the treachery of Michael Gove, the many faces of Boris Johnson, his adoration of Tony Blair.

The former Tory Prime Minister feels deep regret over the EU referendum, but he'd do it all again. We learned that he coached the Queen to involve herself in the Scottish independence referendum. We sympathised with his grief over the death of his disabled son, Ivan. Indeed, David Cameron's best line comes not in his autobiography, but in his response to that Guardian's “privileged pain” editorial . “Death”, Cameron said, chillingly, “knows no privilege”.

So again, what more is there to say? Well quite a lot if you look at this as a book and not a source of news headlines. Despite its deathly dull title, this isn't a bad book; in fact it's very readable, and you can't say that about most political memoirs. The hand – and the wit – of Times columnist Danny Finkelstein, who collaborated with Cameron, shines through.

It's tendentious, of course – this is the former PM's apologia. But Cameron explains complex issues, like the government debt crisis and tortuous EU negotiations, with admirable clarity. Occasionally it is laugh-out-loud funny – something I didn't expect. The chapter where he describes the downfall of Norman Lamont in 1993 is pure Armando Iannucci. The then Chancellor was alleged to have purchased cheap champagne and Raffles cigarettes in a street frequented by ladies of the night. As Lamont's special adviser, or SPAD, the young Cameron had to send Treasury officials off in late night taxis tracking down their boss's movements in insalubrious quarters.

Then there's the time he got lost taking Angela Merkel for a walk in the PM's Chequers estate, then got her stuck in a wire fence, an obvious metaphor for his entanglement with the German Chancellor over EU reform at endless Brussels summits. He tells how at one of them, Mrs Merkel had to be told to turn down the football on her laptop because she'd forgotten to plug in her headphones.

There is a beguiling honesty, too, about his upper class upbringing in a Buckinghamshire Rectory. His loving stay-at-home mother and his eccentric, bibulous and disabled father, who had his own cider house rules that included “never be an accountant”. We also learn how the young Cameron thoroughly enjoyed strutting around Eton in his penguin suit, puffing on a joint, how he revelled in the exclusive lifestyle in Oxford, where he discovered politics and gained a first. He takes you there.

The first half of this book almost reads like an x-ray of the British class system. I wouldn't be surprised if Netflix serialised it, as a modernised Downton Abbey, complete with Bullingdon dinner jackets. He explains that infamous photograph – which also features fellow Bullingdon member Boris Johnson – as naive posing by young men who'd been fascinated by the TV series “Brideshead Revisited”. Well, yes. Weren't we all.

Collins could have titled this book: Effortless – A Study in Privilege. It is a lesson in how class transmits itself through the generations. David gets a summer job in parliament through family contacts. Gets his business grounding in Jardine Mathieson through similar mechanisms. It's the same working for Carlton TV. Connections, connections.

When he enters politics he gets a safe seat in comfortable Oxfordshire. At every stage in his glittering career, Cameron is bolstered by the networks of privilege, but above all by his self-confidence. It's a huge advantage, which allows him to speak to and about foreign leaders without the handicap of social inferiority.

Cameron wisely avoids trying to conceal his origins, still less justify them. Rather than exploit the death of his disabled son, Ivan – indeed, the chapter is quite moving – he turns it into a tribute to the National Health Service. He is what he is: "call me Dave", a scion of upper class privilege who nevertheless realised that the Conservative Party had to change. That it could no longer be – as he repeatedly puts it – “white, male and middle class”.

But he's a Tory, remember, albeit a “progressive” one. Indeed, he was a very right-wing Conservative when he started out, after being radicalised by extreme Thatcherites and American neo-cons at Oxford. He does not apologise for the austerity he imposed on Britain after 2010. There is no mention of the impact of the benefit cap, or the growth in zero hours contracts, or the insecurity: it is simply beyond his ken.

He even boasts that his spending cuts after 2010 were deeper than Margaret Thatcher's in the 1980s. It was all about saving future generations from the burden of public debt, he says. But as someone schooled by economists, he must surely have known that cutting public spending during a downturn is the economics of the Great Depression.

It led to the longest period of wage stagnation in 200 years, a shocking rise in wealth inequality and a punitive assault on the living standards of the least well off. Austerity also indirectly led to the rise of populism. He concedes that there was discontent in parts of Britain among people who were “left behind”, though he puts this down to their inability to adapt to changing times.

Reading his account of his modernisation of the Conservative party it is striking how far race, sexuality and gender themes served to conceal the realities of class division and the pervasive inequality perpetuated by his own policies. I'm not saying that Cameron did not believe in gay marriage, closing the gender gap or driving out racism from the Tory Party. He does sincerely believe that people should not suffer discrimination because of the colour of their skin or the people they love.

Cameron forced through polices that quadrupled the number of women Conservative MPs and he was ruthless with Tory MPs who misused public money during the “duck house” expenses scandal. He was right to do all these things, not just because it helped the Tories change their image and win a couple of elections, but because, as Tony Blair would say, it was the right thing to do.

However, as Marx said, the ruling ideas of the age tend to be the ideas of the ruling class, and this book reveals how diversity has become the ideal of a new elite. It is a new, globalised ruling class, of course: one that doesn't wear a tie, says “f**k” a lot, is open about sex and drugs, and stifles a laugh at “nutters and fruitcakes” of UKIP.

Cameron was a genuine radical who even forced the Tories even to abandon grammar schools. His heart was in the right place, and he respects women and people of colour. But class runs through this book like a stick of rock. While the singer changes, the song remains the same.