Unjust Rewards, by Polly Toynbee and David Walker

Solutions to inequality found on the Clapham omnibus

Picture two toddlers sitting in their pushchairs on the bus to Clapham. They are called Emily and Callum. Emily's family is comfortably-wealthy, while Callum's family is poor. For this reason alone, Callum is three times more likely to die in an accident, and twice as likely to become mentally ill. Even if Callum is clever and Emily is thick, by the age of 10 they will be level at school – and then Emily will race ahead. Callum will, in the end, enjoy 12 years less of life. Polly Toynbee writes: "At Clapham Junction, the two pushchairs bump down the step onto the pavement together and head in opposite directions. Almost certainly forever."

Emily and Callum's story is our national story now. In 21st-century Britain, inequality has become an unbridgeable chasm. The journalist Polly Toynbee has long been a lightning conductor for the right, because she has been the most consistent – and correct – critic of this polarisation. Where they offer blithe assertions of classlessness, she points to the hard sociological evidence showing "birth is now destiny... Parental income predicts who will run the investment banks and who will clean their floors."

Unjust Rewards is written "as an optical aid, to sharpen ways of seeing society's misshapenness," Toynbee and Walker explain. They look at the opposing ends of the inequality-canyon: the richest 10 per cent now own 54 per cent of all personal wealth, and the bottom 10 per cent own less than one percent.

What does Britain look like from the stratosphere? They assemble some City bankers and lawyers in the top 0.1 per cent of earnings and present them with the facts. They gasp to discover that 90 per cent of British people live on less than £40,000 a year. One thinks he is on average income at £200,000. Asked what constitutes poverty, they suggest £22,000 a year – which would mean a majority of British people are in poverty. "I have no idea how they survive on the incomes they have," one banker says. But when it is suggested they pay taxes to start putting this right, they dismiss the proposals as "all kinds of bullshit crap."

What about the opposite end of the telescope? For all the vile Vicky Pollard caricatures, they find a statistically typical single mum in Birmingham: Alison Murray, a 32 year-old whose husband left her. "I never have new clothes, [it's] all charity shop for me and [her sons], but I don't mind that much. It's the things you can't do for them... They never go swimming. They never go to the cinema. They never take a train. They never have a day's holiday." Yes, this poverty is relative, not absolute – but it still hurts. And the chances of her kids moving up and out in Thatcherised Britain are smaller now than for a generation.

One of Toynbee's great strengths as a journalist is that she doesn't just describe problems; she offers solutions. "We can change social destiny, if there is the political will and popular assent for the tax to fund it." It's not sci-fi: Norway abolished child poverty in 2003. Toynbee and Walker report movingly on the government programmes that have made a difference – like SureStart, or one-on-one reading teaching – and call for them to be super-charged.

And, crucially, they demand action at the top. A High Pay Commission should name-and-shame egregious bonuses, and recommend a reasonable national average. The super-rich will scream, but Toynbee and Walker show how hollow their threats are. The entire finance sector – including the City, insurance and high street banks – makes up just 8 per cent of our GDP: less than half of manufacturing, or property services. The number from this industry who would leave rather than pay their fair share is smaller still: only 14 per cent of FTSE chief execs are from abroad, and even McKinsey admits the chances of them packing up are "limited."

No doubt Toynbee will be showered with right-wing abuse for this book. But since it is a brilliant blend of moving human stories, cast-iron statistics and real-world solutions to our great national scandal, those certainly will be unjust rewards.