Part memoir, part political essay, Out of the Ashes aims to "offer a way forward for Britain" following this summer's riots. This is an ambitious task. All the indicators suggest Britain is going backwards economically, socially and politically. But David Lammy hits the ground running as the MP for Tottenham, in north London, and his book demands to be read.

Recalling an encounter with Gordon Brown, he reveals the difficulties of getting across a troubling message from the grassroots. In 2008, the PM summoned him and other ministers to a breakfast meeting in Downing Street. They were invited to pitch any "thoughts, suggestions or concerns" they had. Given the reality of gang activity in Lammy's constituency  an area of north London with some of the highest levels of social deprivation in Britain  he told Brown he was "really worried about knife crime". Pointing out that more and more mothers were visiting his surgeries to voice concerns over their sons' safety, Lammy asked the PM what could be done for these women. "Tax credits," said Brown. "If they're single parents and they're working, they'll be entitled to them." Brown then patted Lammy on the arm, thanked him, and carried on working the room. Problem solved.

Cut to 4 August 2011. Tottenham resident Mark Duggan, 29, is shot dead by police officers from Operation Trident, the Metropolitan Police unit that investigates gun crime in London's black communities. Trident had apparently mounted the operation without informing the local police, thus jeopardising years of relationship-building between the community and local officers. Lammy's "heart sank" at the news, conveyed to him by the borough commander. He cut short a family holiday to return to a Tottenham awash with rumour, speculation and misinformation. Two days later, his constituency was up in flames. Within hours, the unrest spread like a contagion to other parts of the city before snaking its way around the country. He says he predicted the riots. This is a brave assertion to make. It's true, however, that, unlike most MPs, he was born and raised in the constituency he represents. And like many of his constituents, he knows about the challenges of single parenthood: his father left the family household when David was 12, forcing his mother Rose to bring up five children by herself. Aware of the tensions in N17, no doubt he did see the riots coming. After all, he'd seen it happen before.

In 1985, the Broadwater Farm estate in Tottenham erupted. Fuelled by racism, social exclusion, police brutality, poverty and the like, youths took to the streets. Duggan lived on that estate; PC Keith Blakelock died on it. The anger of the rioters, and indeed many pacifists, was articulated graphically by Lammy's predecessor, Bernie Grant MP. "The police got a bloody good hiding," Grant once said. The words were too strong, given that an officer had just been murdered in the line of duty. But those words became the tagline of the 1985 riot. Something political had happened.

The 2011 riots were, on the other hand, "an explosion of hedonism and nihilism", says Lammy. He writes of walking along Tottenham High Road in the smouldering aftermath, a stretch of road that, as a child, he and his father would travel, scooping up droppings from police horses on match days, to take home as manure. Passing the gutted post office he knew as a boy, he is struck by the putrid smell of burning rubber. Elsewhere he finds shopkeepers in tears. The rioters didn't just destroy his neighbourhood, they destroyed part of his history.

Reportage aside, Lammy offers a plausible explanation for what happened. Where Disraeli wrote in the mid-19th century of "two nations", Lammy writes of "two revolutions". "The first was social and cultural: the social liberalism of the 1960s. The second was economic: the free market, liberal revolution of the 1980s. Together they made Britain a wealthier more tolerant nation. But they have come at a cost, combining to create a hyper-individualistic culture, in which we do not treat each other well." Now rights have trumped responsibilities; and freedoms take liberty away from others.

Thanks to the outwardly banal, consumerist nature of the riots, David Cameron was seemingly "on trend" when he proclaimed the riots were "criminality pure and simple". Written off as the work of a "feral underclass", who deserved the draconian sentences they got, this supposedly criminal enterprise looked less a political problem and more one for the courts to deal with. But as Lammy reminds us throughout the book, a continual lack of education, ineffective parental guidance, poor role models, ill-discipline, unemployment and a host of social and developmental ills created the perfect storm for a riot. Yes, the rioters' behaviour was criminal. Yes, people have free will. But go to Tottenham, Hackney, Toxteth, Salford and witness the conditions people are living under. We know that poverty isn't just about a lack of money. It's about a lack of opportunity, prospects, hope. Failures of politics and society further up the food chain played a major part in the riots, as well as craven greed. Lammy points the finger, not just at Thatcher and Cameron, but at Blair and Brown too. This quartet has mortgaged British society, economically and morally. Riots and recession alike are their legacy to us. Ultimately though, it is capitalism and consumerism that are in the dock. "Consumption should supplement our relationships, not become a substitute for them," he says. He quotes a Blackberry message sent by a rioter to one of his young constituents, which in the pidgin text-speak of 21st century Britain, illustrates the flashmob mentality of many of the rioters: "What ever ends [area] your from put your ballys [balaclavas] on link up and cause havic, just rob everything. Police can't stop it." This is freedom "without any sense of duty" he argues. "Our society needs to reconnect with other important, informal regulators of behaviour. Notions of decency towards others. Pride. Shame. Admiration. Scorn."

But this prescription cuts both ways. Simply imploring our feckless youth to join the scouts or go to church to find salvation won't cut it in the current climate. Lammy knows this, which is why his coup de grace is aimed at the moneylenders, and by extension, the politicians that empowered their greed in the first place: "We cannot live in a society in which banks are too big to fail but whole communities are allowed to sink without trace." Cameron, I hope you're listening.

The most authentic, and interesting, parts of Out of the Ashes by David Lammy, MP for Tottenham in north London, involve him talking about his absent father, and the impact this had on the family. It's an often moving story that many of his young constituents will be able to relate to. Lammy also captures well the frustrations of those who became victims during the riots  those whose homes were burnt to the ground and whose businesses went up in flames.

But there is little sense that he has managed to grasp the scale of disaffection felt by those who participated in the riots. In disassociating the initial peaceful demonstration from the riots, he has managed to forget that people at first came out on the streets with good reason. Lest we forget, as he appears to have done, Cynthia Jarrett (in 1985), Joy Gardner (in 1993) and Roger Sylvester (in 1999) and now Mark Duggan all died after incidents involving police in Haringey. Each time, local people mounted demonstrations outside local police stations.

Lammy rashly dismisses the riots as not straightforwardly borne out of despair, frustration and a lack of trust in the authorities  especially the police. He seeks to dismiss these emotions, preferring to view all who participated in these events in the same light. There is little mention of the heightened sense of disaffection, marginalisation and powerlessness that was felt by many of Duggan's close friends, in the immediate aftermath of his killing. Lammy shows no understanding of the reaction of the community to the "news"  it turned out not to be the case  that Duggan had been killed in a shootout where he had fired first at armed police officers. And he fails to acknowledge that this very public smearing of Duggan's name was the tipping point that bought family and friends on to the streets of Tottenham. Instead he chooses to lump all the events of early August together  from Tottenham to Salford, black and white, looters and rioters.

In a political analysis that uses the events of early August as its thread, he argues that the riots were the outcome of consumerism, family breakdown, loss of moral compass and the role of gangs: he has a wider goal, of course, but he misses the reality on the ground. He seems to suggest that all of the rioters were looters; as such they are identified as being victims of a hyper-individualistic society and motivated by nothing more than simple greed: "The riots were an explosion of hedonism and nihilism. People with little to lose lashed out at authority and took what they wanted. The violence and the looting were driven by the sense that, for a few nights only, people could do whatever they pleased."

Lammy tries, unsuccessfully, to argue that the events of 2011 have little in common with the riots of the 1980s. He seeks to contrast the disturbances of Broadwater Farm, which followed Jarrett's death, with the Tottenham riots. However on the very first page he makes a mistake which many, especially those who like me were arrested in the Broadwater Farm investigations, find hard to forgive. Lammy states that 69 people were arrested as a result of the police investigation into the riots and murder of PC Blakelock; in fact, 369 people were arrested, 69 charged, 35 found guilty. This figure does not include the Tottenham Three, who were sentenced for Blakelock's killing, but later released as innocent victims of miscarriages of justice. This is important as it still fuels the community's mistrust of the police and judicial system. It's a mistrust that Lammy does not even mention.

Surprisingly he makes no mention whatsoever of the 6,892 stop and searches that were carried out in the borough in the two months preceding the riots. As black people are allegedly four more times likely to be stopped than white people, this would mean that 5,513 of those stop and searches were carried out on "non-whites".

Rather than exploring how this aggressive policy might have fed into the shooting of Mark Duggan, or how the police failed properly to communicate with the family after his killing, or their poor handling of the peaceful demonstration, Lammy chooses to emphasise that it "was not local police who fired the bullet that killed Mark Duggan. Mark Duggan was killed by Operation Trident  and it was a distant control station that called the shots [sic] during the riots".

It's shocking that Lammy has very little to say about the things that really matter in areas such as Tottenham, and indeed matter in terms of the country's future. There's almost nothing about schools and education. Lammy was lucky enough to have had a private education, but this should not prevent him from addressing the need for an education system that raises aspiration and gives hope to kids, from places such as Tottenham, that they can achieve despite their disadvantages; an education system that does not simply set targets and then excludes those that it thinks will not help it to achieve its objectives; an education system that values pupils equally regardless of race or background, one that does not disadvantage black boys who persistently fill the ranks of the permanently excluded and not the ranks of the heavily-qualified.

Perhaps he should have thought for longer  might it be the case that in writing his book, so soon after the events, Lammy reveals that opportunism is not just the sport of looters?