God bless Britain’s political class, for in their capacity for happy self-absorption they are as reliably easy to please as a puppy. Just chuck them the right chew toy.

Who won last night’s head-to-head, Boris or Jeremy? Gnaw gnaw. What is George Osborne playing at? Snuffle, snuffle. Doesn’t young Matt Hancock look tortured these days? Slobber, slobber. And so politicians and pundits paw away, the existential questions facing an entire country somehow never quite as rousing as the latest gossip from Versailles.

Still, at some point this summer, a few yawningly prosaic points will intrude. Such as how our tousle-headed Nero hopes to govern with a working majority of just three MPs – and that’s counting on the support of the Democratic Unionists, who have proved to be the most unreliable partners since … well, Boris Johnson himself. How he plans to see off the vote of no confidence that Jeremy Corbyn is preparing to put down, and which may be backed by anywhere up to 30 Conservative backbenchers. How he will secure the passage of a Queen’s speech, given parliament has just sat for the longest session since the civil war because Theresa May couldn’t get one through.

However commanding his lead among Tory activists, Johnson is about to form the most fragile government seen in Britain for almost 50 years. What’s more, he’ll do so burdened with one huge problem that not even May had to face: a recession.

While at Westminster they dare not even whisper the word, City folk and economists are already discussing the prospect in tones of grim resignation. Speaking in Bournemouth last week, Bank of England governor Mark Carney warned of a “sea change” in the world economy. The UK economy didn’t appear to be growing at all, he noted, “and is heavily reliant on … household spending”.

The figures back him up. The most watched surveys of British businesses, released in the past few days, suggest the private sector is already shrinking. In the construction sector, which has just had its worst month since the immediate aftermath of the financial crisis, they now talk of “quicksand”. Manufacturing has been pole-axed, while out in the much larger service sector things look utterly moribund. Last week, it was briefly cheaper for the British government to borrow over five years than for two – the first time that has happened since just before the death in 2008 of Lehman Brothers. Even in a world turned upside-down by central banks pumping hundreds of billions of dollars into money markets, that is usually taken as indicating that a sharp slowdown lies around the corner. This one will be nowhere near as disastrous as the crash of 2008-9; but it will underline how far the world remains lodged in the shadow of that crisis.

“The early evidence suggests the UK is already in a recession and that we’re just waiting for more data to prove it,” says David Blanchflower. As a rate-setter at the Bank of England in 2008, he was one of the few policymakers to spot that crash coming; but when central bankers and government ministers did finally wake up, at least they had plenty of firepower to draw on. Within a few months, Blanchflower and his colleagues slashed the base rate from 5.25% to 0.5%. Having put up one hell of a fight back then, the bank is in no position to go into another today: a bombed-out economy means that a decade later the base rate is still holed below 1%.

The UK is suffering an intense version of an international problem. Around the world, central bankers from the eurozone to Australia can see a sharp slowdown on the horizon – and are warning they have little in the drawer to head it off. As for governments: in the US, Donald Trump spent most of his political capital on a tax cut for the rich in 2017, while any European government that defies the rule of austerity risks destruction, as Greece’s former prime minister Alexis Tsipras has learned over the past four years. Ten years ago, China helped save the world by launching a spending programme worth nearly $600bn – throwing up airports and high-speed rail lines within months. Beijing will not do the same this time around.

In the UK, as I wrote here last week, Johnson is talking of a hard-right version of a Keynesian stimulus, with tax cuts for the rich and huge bungs for big corporates. That will steal Corbyn’s clothes as the anti-austerity party leader, but it will be of no help to the mum living off a fiver while waiting for her universal credit to come through, or to the teachers whipping up a food bank for their pupils. Not with Sajid Javid as potentially the first chancellor to profess both love of libertarian high priestess Ayn Rand and his total unwillingness even to break off a family holiday to save the steel industry.

Put that picture together, and the outline of something truly frightening starts to emerge. A ruling party on its last legs in a political system sapped of nearly all legitimacy. A country that has spent most of the decade mired in the weakest recovery for 300 years – as Blanchflower describes it in his new book, Not Working: Where Have All the Good Jobs Gone? – which is now giving way to recession. And a political class that still kids itself it can get a better Brexit deal out of the rest of the EU, or even that it will survive a crashing-out with only a few nicks and grazes.

This might make good copy in Westminster, but the turbulence of either scenario will push businesses and families to the wall in the Midlands, Wales and the north. As Birmingham-based economist Paul Forrest points out, in the run-up to the last exit date Jaguar Land Rover announced the shutdown of four plants in Castle Bromwich, Halewood, Solihull and Wolverhampton for two weeks, to avoid “potential Brexit disruption”. Imagine what that employer of 43,000 staff might do this autumn. Then think of Nissan, Honda, Peugeot … and imagine how the speculators will pile on the pound, pushing it down to $1.10 and then below.

“My background is in emerging markets,” says Forrest, “and the last time I saw this amount of pent-up chaos was when Russia devalued in 1998.” Should you need reminding, that crisis impoverished middle-class Russians and wiped out the Moscow ruling class.

Throughout my adult life, Britain’s political system has got by on bluff and bluster. On ever-cheaper credit for the masses and dark money for the party funders. On half-understood technocratic management by unelected officials and masterful presentational skills by the politicians. On a housing market that just kept rising like an impossible soufflé and the pretence that the Adults Were In Charge. Margaret Thatcher, Tony Blair, David Cameron – all of them got by on versions of the same strategy. It was always a cheat, and perhaps the one good thing about the poisonous 2016 referendum was how it illustrated how many people had sussed they were being conned. And now, under Johnson, the entire bluffers’ system is on the verge of disintegrating, with no glimmer at all of what may replace it.

• Aditya Chakrabortty is a Guardian columnist