Can you hear it: the theme from The Great Escape, and the hum of Spitfire engines? Such is the mood music that echoes around many leading Brexiteers: men who seem to have all but forgotten the comparatively recent conflict centred on Northern Ireland but affect to be consumed by the distant stuff of Dunkirk, the blitz and VE day. Question marks still hang over how we will get to a general election, but some aspects of the looming campaign seem certain. If Boris Johnson somehow gets a deal with the EU and manages to steer it through parliament, he will presumably continue to talk about a country destined to stand apart from Europe and set an example to the world of derring-do, mention Winston Churchill and use a lot of martial metaphors. If everything comes to grief and he has to request the dreaded extension, that stuff will doubtless be accompanied by rhetoric about remainer MPs and judges, the obstinate and unreliable French and Germans, and a view of Ireland as a country that has ideas above its station.

Deal or no deal, all these things will presumably be voiced by Nigel Farage and the Brexit party – who, like their fellow Brexiteers in the Conservative party, have a vision of Britain unbound that harks back to the days of empire, and a loud obsession with Britain’s role in the second world war, or their imagined version of it.

To anyone under 40, these things must surely seem weird beyond words, which ought to give cause for hope

After all this time, these things are ingrained in the Brexit moment and the spaces where politics meets culture, probably for the foreseeable future. Johnson fumes about parliament’s “surrender bill”, as those increasingly irksome No 10 “sources” warn of MPs colluding with “foreign powers”. Nigel Farage rallies begin with the sound of air-raid sirens. Allies and supporters of the prime minister regularly bring up his Churchill fixation, and claim that the spirit of the man on the £5 banknote is being channelled anew, even though what is afoot is obviously much less noble than that. Last week, when he and his people decided to blame Angela Merkel for their waning hopes of a deal, they surely knew what they were doing: tapping into a rich seam of British prejudice that was made clear last week in a Twitter meme put around by Arron Banks and his accomplices at Leave.EU, only to be deleted. “We didn’t win two world wars to be pushed around by a Kraut,” it said: a view of 20th-century history traditionally voiced by English football hooligans after 12 lagers and too much sunshine.

Banks was born in 1966; Johnson and Farage in 1964. Mark Francois, the Conservative MP who needs no encouragement to hold forth about his father’s wartime service and the necessity of standing up to Germany, entered the world in 1965. By the time they were even aware of such things, the end of the second world war was a quarter of a century away, and what remained of the empire was being mocked on TV by David Frost (“Fiji, Mauritius, Swaziland, the New Hebrides Condominium … and sweet Rockall”). But more than 50 years on, their secondhand nostalgia seems to have found a ready audience, as keen as them on the idea that Britannia could once again rule the waves and stick it to the continentals, if only the people Johnson calls “the doomsters and the gloomsters” would let her.

Facebook Twitter Pinterest ‘Allies and supporters of the prime minister regularly bring up his Churchill fixation.’ Photograph: Danny Lawson/PA

That the prime minister often presents this stuff wrapped in a sense of the absurd only highlights how ludicrously misplaced it all is. This is not just because of our impossible historical distance from the events these people eulogise and the social transformations that have happened in the meantime (self-evidently, to yearn for the spirit of pre-50s Britain runs the risk of celebrating a country that was monoculturally white and ridden with bigotry, and an imperial ideal racist in both theory and practice). Decades of cultural history have also undermined just about every aspect of the Brexiteers’ view of things.

The first Colonel Blimp cartoon, I was recently reminded, appeared in 1934. With no little prescience, it was captioned: “Gad, sir, Lord Beaverbrook is right. Splendid isolation is the policy for England. If we refuse to trade with the dashed foreigners in Ireland, Wales and Scotland … the future will be in sight.” Later on, didn’t the great cultural explosions of the 60s decisively pull us away from the last traces of wartime jingoism, as the union flag was reinvented as a totem of camp, and the supposed glories of war and empire were suddenly sent up? In the Beatles’ 1967 masterpiece A Day in the Life, the enervated, gently mocking way that John Lennon sings one line in particular – “The English army had just won the war” – seems to open up the possibility of a whole load of national delusions being subverted.

And so it proved: the so-called satire boom was already in full flow – and then along came Monty Python’s bursting of every pompous English balloon, and even Dad’s Army, with its affectionate portrayal of the farce and hilarity woven into the country’s finest hour.

When the UK’s descent into economic decline was met with Margaret Thatcher’s flag-waving and the rise of the National Front, it fell to the new generation of punks to try to explode their fantasies (listen to such songs as the Clash’s Something About England, the Jam’s Little Boy Soldiers, or the Sex Pistols’ ageless God Save the Queen). And so this strand of popular culture has gone on, speaking directly to millions of people and shaping their understanding of the country they live in. In the midst of the current madness, a good example is the Northampton-born rapper Slowthai, who has Caribbean, Irish and English ancestry, and styles himself as the Brexit Bandit. The title track of his debut album speaks volumes: “I said there’s nothing great about the place we live in/ Nothing great about Britain/ Sip a cup of tea whilst we’re spittin’/ There’s nothing great about Britain.”

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Yet the old illusions refuse to die. To state the obvious, much of the blame for this country’s enduring mixture of hubris, nostalgia and Europhobia can be laid at the door of the tabloid press. It is responsible for framing everything from Germany v England football matches to Jacques Chirac’s opposition to the Iraq war in terms of unfinished business from 1939-45, and the idea that many European countries owe us a debt of gratitude they have never paid off. But there are also other, more insidious influences at work. When the likes of Farage and Francois talk about the war, I hear not an authentic echo of the struggles and victories of 1939-45, but the big-selling and very stupid comics I used to buy as a child in the late 70s: Warlord and Victor, replete with stories of “Jerries” and “Japs”, such characters as Union Jack Jackson and Bomber Braddock, and the basic message they carried – that there was no finer expression of Britishness than charging at the enemy, hoping for the best.

To anyone under 40, these things must surely seem weird beyond words, which ought to give cause for hope. So too might one basic fact about the Brexit moment: that the comical fantasy of a belligerent UK blazing its own trail is already being tested by reality. There again, given that the fictions of war and empire have endured for so long, would they really suddenly wither away? The results of the election – or, perhaps, another referendum – will give us an answer of sorts: one of the reasons why the next few months will decide not just who is in power, but the kind of place this conflicted, nervous country is going to be.

• John Harris is a Guardian columnist