Slap bang in the middle of this week falls one parliamentary event likely to be greeted with near-silence. When Philip Hammond stands up tomorrow afternoon to deliver his spring statement on the health of Britain’s finances, he’ll know in his bones that it will provoke no feverish excitement among lobby journalists, nor command the front pages. Given a major economic policy announcement, newsreaders would previously devote their bulletins to his figures and forecasts; this time they will probably give it a mere moment’s notice. And who can blame them?

A prime minister potentially faces her last days in office, her cabinet is in all-out mutiny and the country teeters on the brink of its biggest foreign policy decision in almost half a century. Herein lies a glorious chance to treat politics as Netflix, to gossip about court intrigues among Boris and Amber and Jacob, to refer in am-dram tones to Cox’s codpiece and the Malthouse compromise. Presented with all that, which puritan would plump instead for Spreadsheet Phil and his dry-bread sums?

So imagine the pathos inside No 11: Chancellor Hammond, writing the words / of a sermon that no one will hear / no one comes near. Yet in all this, one thing seems to have been entirely forgotten. By ignoring such fundamentals as economic conditions, the political class is displaying precisely the analytical myopia that led to it being blindsided by the Brexit vote in the first place.

Because while the Saj has been mentally measuring up the curtains at No 10, and Liz Truss has been honing her Instagram feed, the British economy has been edging closer and closer to a downturn. That’s right: the tepid, real-pay-freeze economy you’ve suffered for the past few years was as good as it got, and now, according to the Bank of England, the UK stands a one in four chance of tipping into a recession this year. And whatever the promises from Liam Fox and co, we won’t export our way out of this one because the outlook for China and Europe is darkening while the US is fast coming off the sugar rush induced by Donald Trump’s tax cuts last year.

Perhaps you have heard so many mutterings about a no-deal crash that a recession no longer sounds so terrible. But remember that the average British worker is still earning less after inflation than they were in 2008, and that the way many have sought to keep up their living standards is by borrowing. The result is that, even before any serious downturn, the Bank’s research suggests around 6.5 million households – almost one in three – are already in some form of debt distress.

That is the grim backdrop against which Hammond speaks on Wednesday; and, true to dismal form, he is unlikely to do much to alleviate it. In 2016, as soon as he became chancellor, to save the economy Hammond should have repudiated Osbornomics. Sure, Theresa May has declared austerity to be over. And the chancellor has promised fellow Tories that, if they behave like good chaps and back her deal, he’ll splash out. But the sums under discussion are minuscule.

Here is one number to bear in mind afternoon: to get day-to-day government spending proportionately back to where it was before the banking crash, the Resolution Foundation thinktank calculates that Hammond would need to find an extra £56bn each year. That puts any minor giveaway to the regions into perspective, and also brings home how far the Conservatives (with cover provided by the Lib Dems, never forget) have slashed at the public realm this decade. Nine years of historic cuts by George Osborne and his successor has left the British public sector permanently smaller and more enfeebled. Just think of the stories revealed in a Guardian investigation last weekend: of teachers now cleaning schools, of primary school pupils being sent home early, of children with special needs getting less and less attention. All for the sake of a few pennies off the corporation tax rate.

The carnage was deliberate, as David Blanchflower, former rate-setter at the Bank, writes in his forthcoming book Not Working: Where Have All the Good Jobs Gone: “The fact that austerity has never worked matters not. It was a unique political opportunity for the right to reduce the size of the state never mind the social and economic consequences. [The government] did a reverse Robin Hood: taking from the poor and giving to the rich.”

As economics, Osborne’s cuts were always going to be a failure; as class war, however, they were a triumph. Until, that is, the Brexit vote came along and the victims of Osbornomics got a chance to take their revenge. A recent study of voting patterns by the Warwick University economist Thiemo Fetzer concludes: “The EU referendum could have resulted in a remain victory had it not been for a range of austerity-induced welfare reforms.”

Fetzer is not arguing that all leave voters were affected by Osborne’s cuts; he is observing that there were enough to tip the balance of a very close vote. Osborne’s cynical strategy of imposing huge cuts then allowing tax-paying migrants to be blamed for A&E waiting times, rising class sizes and the dearth of council housing backfired spectacularly. The result he fought against was landed thanks to the very policies he imposed on the country.

The politicians who dominated from the banking crash up until the Brexit vote, whether Gordon Brown and Ed Balls or Osborne and David Cameron, worked so hard to shrink the bounds of what was politically possible that they were ultimately deposed by politicians whose very specialism was promising the impossible. Just think of Boris Johnson and his wretched bus, Liam Fox and that long queue of imminent trade deals, and of course the Backstop Queen, Theresa May.

The great frustration of this age is that the political classes keep treating the deliberate immiseration of so many people and places in Britain as a sideshow to the high drama of Brexit. In economics, there is a growing agreement that the 90s and 00s, sometimes called the Great Moderation, were in reality the breeding ground for the banking crash and the crisis that has followed.

Westminster has gained no such self-knowledge. Supposed moderates such as Anna Soubry and Chris Leslie continue to support austerity and the extreme economics that produced the extremist politics they so deplore. It is the self-styled centrists who have created today’s polarisation, only they cannot see it. Until they do, we are stuck in a groundhog day of meaningless votes and purposeless austerity. The heirs to Blair have ended up giving us 1997 in reverse: Things Can Never Get Better.

• Aditya Chakrabortty is a Guardian columnist and senior economics commentator