As Verbal Kint says in The Usual Suspects: “The greatest trick the devil ever pulled was convincing the world that he didn’t exist.” And, as we have fresh reason to reflect this weekend, it appears that certain key Brexiteers may have played a similar trick. The popular view of them as a bunch of cheeky chaps is being challenged: their actions increasingly regarded as fitting the agenda of a global network of the populist right that stretches from Moscow to the Trump White House via the surging nationalist parties of continental Europe.

Stories in the Observer and Sunday Times about key figures in the Leave.EU campaign and their connection to Russian diplomats and businessmen are scoops of degree rather than kind. We have known for two years that Arron Banks, the pro-Brexit tycoon, and his closest henchman, Andy Wigmore, visited the Russian embassy in November 2015, just as we have long been aware of the links between Leave.EU and the Trump campaign.

What has now been revealed is the sheer scale of these contacts – including a lunch between Banks, Nigel Farage and Alexander Yakovenko, the Russian ambassador, just three days after the Leave.EU team had been granted an audience with president-elect Trump in November 2016. It appears that there were multiple meetings between Banks, Wigmore and senior Russian officials between 2015 and 2017. It also appears that the ambassador offered to help Banks broker a deal involving six goldmines in Siberia. This does not seem, in other words, to be routine schmoozing or glad-handing. It has the whiff of a nexus, suggesting a purpose, or multiple purposes.

Small wonder that Damian Collins, chair of the digital, culture, media and sport committee, is so keen to interview Banks and Wigmore as part of his inquiry into fake news and digital guerrilla warfare – a field in which Russia leads (full disclosure: I gave evidence last year to the inquiry alongside Carole Cadwalladr, the co-author of this weekend’s Observer report). On Friday, the Leave.EU duo told the committee they would not appear. On Sunday, however, it appeared that Collins had been led to believe that Banks and Wigmore will, in fact, turn up. The nation awaits with excitement.

Pollsters will tell you the dominant public emotion now associated with Brexit is impatience. In less than a fortnight, Britain will mark the second anniversary of the EU referendum with nothing like a coherent negotiating position. This week, Theresa May will seek to fend off amendments to the EU withdrawal bill, having spent the past few days desperately trying to maintain a semblance of cabinet unity. No wonder the message from voters is: get on with it.

In which context, why bother with the minutiae of a campaign fought and won two years ago? The answer is that this concerns something greater even than Brexit – which is how we conduct politics, the lamentable state of political discourse and whether we mind. Exhibit A is a snappily readable book, The Bad Boys of Brexit, that appeared under Banks’s name in 2016, but was written with the help of journalist Isabel Oakeshott. The book is a remarkable exercise in political pantomime.

It presents the Leave.EU team not as bunch of chauvinistic nationalists but a gang of lovable rogues, culturally situated somewhere between Hancock’s Half Hour and Guy Ritchie’s early movies – the ones in which everyone had a nickname like Bacon, Soap or Hatchet Harry. The effect is to present what one might describe as the paramilitary wing of the Brexit movement as well-meaning Del Boys who only wanted to liberate the British from the tyrannous grasp of Brussels and the London liberal elite – and (why not?) have a bloody good laugh along the way.

Hence, the key meeting with Yakovenko is depicted as a boys’ boozy lunch in which the ambassador plies the lads with a bottle of vodka he claims was “one of three in a batch made for Stalin”. Banks pronounces it “bloody good” and asks for another. What a geezer!

Most intelligence tradecraft is deliberately banal. Did the Bad Boys of Brexit really not know they were being played, or just not care? Was it all too much fun to bother about the boring stuff that lawyers, liberal journalists and remoaners bang on about? I mean: why let the commercial future, global influence and national security of the country get in the way of a good lunch?

And if all this strikes you as a bit “inside baseball” – stories about journalists, campaigners and specialist political books – think again. This is a parable of geopolitical imbalance, culture wars and deep political sickness. For here is where we seem to have ended up: under our noses, a well-developed network of far-right and nationalist forces seems to have arisen, apparently digitally mobilised and funded by Russian state actors; the law regulating elections, campaigns and referendums is woefully out of date (passed four years before Facebook was launched); Moscow is laughing at the rest of the world as Trump pleads its case at the G7; the far-right swoons over Vladimir Putin; and Jeremy Corbyn misses no opportunity to give the Russian president the benefit of the doubt over the use of nerve agents on British soil and the deployment of chemical weapons in Syria by his puppet in Damascus.

This week, as the Commons votes on the very future of this country, don’t forget how we got here; how badly we underestimated the populist right; and how the leader of the opposition tends to make things easier for Putin, too. Still laughing?

• Matthew d’Ancona is a regular Guardian contributor