This year will mark the 50th anniversary of a musical masterpiece that continues to speak illuminating truths about the impossibility of the human condition, and how people from these islands tend to cope with it. Pink Floyd’s The Dark Side Of The Moon was released in March 1973, as the last traces of postwar optimism gave way to mounting economic strife and international tension. The response it offered was twofold: a call to empathy and mutual understanding, and the pointing-out of a national trait that this writer – among many others – has probably quoted far too much. It comes nearly six minutes into a song simply called Time: “Hanging on in quiet desperation is the English way.” As a new political year begins, those nine words seem more apposite than ever, and they snugly fit one defining fact of our national predicament: that the wreckage of Brexit is all around us but our politicians will still not acknowledge it. The evidence now encompasses reduced trade, diminished investment and the fact that the UK has been the only major economy not to have returned to its pre-pandemic size. Brexit has resulted in a hit to tax revenues estimated at an annual £40bn – enough to have prevented 75% of the spending cuts and tax rises that were announced in November. Meanwhile, amid impossible passport queues and howls of pain from businesses now tied up in red tape, stories that symbolise the folly of our exit from the EU seem to arrive at least one a week. Just before Christmas, for instance, it was reported that the Metropolitan police would now be buying armoured ministerial cars from the German manufacturer Audi because no UK firm was “able to meet the requirements of the tender”. Here was more proof of the supply-chain problems that are afflicting British producers, and a malaise that has caused annual UK car production to fall by more than half since 2016. The government responds to such news with its usual ludicrous evasions: “I don’t deny there are costs to a decision like Brexit,” said Jeremy Hunt in November, “but there are also opportunities, and you have to see it in the round.” Meanwhile, even now, Tory zealots cling to the belief that life outside the EU could still deliver all the promised prosperity and general magic, if only ministers would try harder. A good example: led by Jacob Rees-Mogg (who is apparently giving serious thought to being the next Tory leader), MPs are pressing Rishi Sunak to stick to a deadline of 31 December 2023 for “reviewing or revoking” EU laws that still apply to the UK, and imagining that the resulting legislative pyre will produce some kind of economic phoenix. The truth, as ever, is more prosaic. The task will involve hundreds of Whitehall civil servants forensically assessing nearly 2,500 pieces of retained EU legislation, and the CBI says the plan is likely to produce “a further drag on growth”. What Brexit has done to Tory politics now goes beyond the party’s interminable debate about what exactly life outside Europe should entail, and deep into Conservatism’s collective psychology. Since the 2016 referendum, the English political right – by which I mean a cacophony of voices, including Conservative MPs, the Mail and the Telegraph, and the kind of pundits now given a megaphone by GB News and TalkTV – has become steadily more eccentric and unhinged. As far as basic economics is concerned, they endlessly deny the existence of gravity. But they now make much more noise about climate action, Meghan Markle, the BBC, the content of dictionaries and whatever other “woke” ghouls are irking them. This is partly a deliberate distraction from Brexit’s catastrophes. But it is also the kind of displacement activity that was always going to take hold once these people’s defining project had turned to dust. And Labour? The tensions of Keir Starmer’s position are translated into denials of things that are self-evidently true. In early December, he claimed that “there’s no case for going back to the EU or going back into the single market”, and only “a very good case for making Brexit work”. Amazingly, he and his colleagues also rule out any return to the EU’s customs union. The reason this once-devout remainer doggedly sticks to these lines is obvious: even if opinion polling suggests that residual popular belief in Brexit is now ebbing away, the Labour party has to secure the support of people who voted leave in 2016, switched from Labour to the Tories in 2019, and would supposedly greet any talk of revisiting the basics of Brexit with anger and dismay. But that does not make what he says any less absurd, nor detract from the depressing sense of a Westminster conversation that omits modern Britain’s most defining fact. There is real danger here. The grifters and chancers who took us out of the EU are still around, threatening their usual mischief. Nigel Farage and his Reform party are apparently planning to field 600 candidates at the next general election, and amid widespread resentment about Brexit’s false hopes, even darker forces may also fancy their chances. “Britain is broken,” Farage says, but for fear of questioning Brexit itself, no one in politics seems minded to point out that he is among the key people who broke it. A huge truth is thereby being ignored, which goes back to the 1930s, if not before. If you don’t want politics flooded with betrayal myths and conspiracy theories – which have a much greater purchase on public opinion than anyone in politics and the media currently seems to realise – then do not ignore uncomfortable facts. When mainstream politicians indulge in denial, demagogues often make hay. As 2023 unfolds, the gap between Brexit’s delusions and our everyday reality will become increasingly inescapable. The Tories’ internal strife and poll woes will go on, but Labour will also be confronted with questions it will no longer be able to avoid. Running through everything will be a massive question about what happens next: how can you even begin to think coherently about the UK’s long-term prospects when any truthful discussion of the present is off limits? Two more lines from the aforementioned Pink Floyd album evoke the essential problem: “Every year is getting shorter, never seem to find the time / Plans that either come to naught or half a page of scribbled lines.” This is what Brexit has done not just to politics, but our sense of the future. Will we hang on in quiet desperation for another year? John Harris is a Guardian columnist