“There is no money, and the Bredins can’t afford to divorce.”

The first four words opening my new novel, The Lie of the Land, come from a famous note left by a Minister in the last Labour government to the new Tory one.

Novelists, or at least novelists like myself who write about contemporary life, are never happier than when a nation is plunged into crisis. One of the meanings of “novel” is, after all, news, and while bad news is never welcome, it does generally tend to get noticed by readers.

My quarrelling couple are forced by the recession and loss of their jobs to move from their valuable and comfortable North London home to a cheap and uncomfortable rented house in North Devon, where their struggles are part of a bigger picture. Above all, it’s about what it’s like to move from the kind of life many urban professional couples still enjoy, with an income of over £200,000 a year to one well below the national average of £27,600 a year. Just how bad is it to try and feed a family of three adults and two children on £80 a week? How often can you use a car – the only form of transport in most rural areas – and fill the oil tank for your heating? Why are there so many food banks, and what does it feel like to work night shifts in a factory instead of swanning off on a Gap Year?

I’m interested in all these questions because of this: in fiction, money is the new sex. Where Jane Austen had no qualms in telling you that Mr Darcy in Pride & Prejudice had an annual income of £10,000 a year, or that EM Forster’s Schlegel sisters in Howard’s End each have an income of £600 a year, we are now not told anything about characters’ income and assets.

Ian McEwan’s top surgeon in Saturday, Martin Amis’s scriptwriter in Money, Rachel Cusk’s divorcee in Outline all live lives of some privilege, but their income is a mystery. At the other end of the scale, we know all about billionaire Christian Grey’s enthusiasm for sado-masochism, but nothing about his income. It would at least make him more two-dimensional.

Thomas Piketty’s book Capital points out that, up to the First World War, novelists from Austen to Trollope to EM Forster could describe specific sums of money belonging to their characters because from 1814 to 1914, there was very slow inflation. For a hundred years, Mr Darcy’s £10,000 a year was intelligible to readers, and so was the average income of £30 a year. These were stable reference points that everybody could understand as marks of status or the lack of it.

Only after the First World War, when major European governments left the gold standard, did inflation gallop away. One consequence of this was that money virtually disappeared from literature, not only in Europe but in America. It took until the 1990s for the level of wealth and disposable income to stabilise and return to levels equal to those observed in the eighteenth and nineteenth centuries.

It’s no coincidence that John Lanchester’s novel Capital, published after the crash of 2009, tells us not only what kind of annual bonus (£1 million) its banker protagonist expects, but what the loathsome Zimbabwean ticket inspector Quentina might generate if she works 250 days a year. (It’s £375,000 per annum, of which Quentina gets £12,000 plus four weeks holidays and no health or pension benefits.) We still understand what those sums mean because over the past ten years, we have had zero inflation. We are also, at last, much angrier about the gulf between the haves and have-nots.

Of course, contemporary novelists may steer clear of depicting money because fewer and fewer of us now make much of a living at all: we just don’t know from personal observation how the rich or well-off now live. Another reason is that money has slipped as an indicator of status. My generation grew up less bound by financial constraints than by our capabilities of individuals – as Tony Blair’s government liked to say, “it’s not where you’ve come from but where you’re going to that matters.”

That era, however, seems to be fading. According to a new report in the Economist, no country in Europe has such a big gap between rich and poor as Britain. It is notable that of the contemporary novelists who do write about money in books like Lionel Shriver’s So Much For That, Rohinton Mistry’s A Fine Balance, Alan Hollinghurst’s The Line of Beauty and Zadie Smith’s NW – most are gay, foreign or from an ethnic minority.

I wanted to write The Lie of the Land because I could see that urban people are not aware of how awful things have become for those in the countryside. Those in the city don’t understand that when milk costs more to produce than to sell, dairy farming goes out of business. That when wages are kept depressed, indigenous people will not be able to take the jobs that immigrants, crammed into caravans or substandard housing will still accept. That when one part of the country has money, and the other does not, a democracy will be violently destabilised, and disasters like Brexit happen.

Fiction must be honest about this, because fiction, far more than journalism, is a way of feeling the reality of other people’s lives. Everything to do with money, from paying taxes to public spending, affects everyone in a civil society, and most of all children. Some of the very worst and most idiotic things currently being done to poor families seem to have come about because those in power have never been poor, or imagined what it’s like to try and live on Universal Credit: or worse, because they have, like those exposed in the Paradise Papers, put money above humanity. We need to awaken the conscience of the nation: we need, once again, to put money back into fiction.