Do you find Brexit a kind of slow-burn, psychological thriller box set in which all of humanity’s worst characteristics compete for supremacy? Then stay tuned because we’re approaching a truly climactic episode.

The comparatively benign themes of ignorance and idleness have been having the run of things for a while now, but the conflict between mendacity and outright racism (which is nothing if not honest), has been building almost since day one and its showdown is about to come.

On Sunday, Theresa May made clear she has given up hope of leaving the customs union. We know this for certain, not because it was on the front of The Sunday Times, but because Downing Street later issued a statement denying it.

In March of last year, Downing Street did exactly the same when asked if there was going to be a general election. If you’re interested in the exact quote from Downing Street, two weeks before Theresa May stood – in Downing Street – announcing the election, it’s here: “There isn’t going to be one. It isn’t going to happen. There is not going to be a general election.”

Already, the approximately seven people in the UK for whom the referendum was all about free trade and Britain signing its own trade deals are furious.

“Leaving the EU while staying in the customs union is the worst of all worlds,” writes Daniel Hannan, their spirit leader, in The Daily Telegraph. “Worse than full EU membership. That is precisely why some MPs and peers are pushing it.”

But the concentration of this outrage and its ring-fenced nature should finally tell Hannan and his friends the one thing about Brexit they have always been too cowardly to admit, ever since they stoked racist sentiment and won.

That Mr and Mrs Brexit don’t care about free trade, they don’t care about the customs union. They care about immigration. They care about leaving the single market, which means taking back control of our borders.

It is always worth returning to the elderly gentleman whom Channel 4 News stopped on the streets of Barnsley not long before the 2016 vote took place. “It’s not about trade, or Europe, or anything like that. It’s all about immigration,” he told them. “It’s about stopping Muslims coming into this country. The movement of people in Europe, fair enough. But not from Africa, Syria, Iraq, everywhere else, it’s all wrong.”

Brexit threatens life on the Irish border: in pictures Show all 15 1 /15 Brexit threatens life on the Irish border: in pictures Brexit threatens life on the Irish border: in pictures An abandoned shop is seen in Mullan, Co Monaghan. The building was home to four families who left during the Troubles. The town was largely abandoned after the hard border was put in place during the conflict. Mullan has seen some regeneration in recent years, but faces an uncertain future with Brexit on the horizon Reuters Brexit threatens life on the Irish border: in pictures A defaced ‘Welcome to Northern Ireland’ sign stands on the border in Middletown, Co Armagh Reuters Brexit threatens life on the Irish border: in pictures Mervyn Johnson owns a garage in the border town of Pettigo, which straddles the counties of Donegal and Fermanagh. ‘I’ve been here since 1956, it was a bit of a problem for a few years. My premises has been blown up about six or seven times, we just kept building and starting again,’ Johnson said laughing. ‘We just got used to it [the hard border] really but now that it’s gone, we wouldn't like it back again’ Reuters Brexit threatens life on the Irish border: in pictures Farmer Gordon Crockett’s Coshquin farm straddles both Derry/Londonderry in the North and Donegal in the Republic. ‘At the minute there is no real problem, you can cross the border as free as you want. We could cross it six or eight times a day,’ said Crockett. ‘If there was any sort of obstruction it would slow down our work every day’ Reuters Brexit threatens life on the Irish border: in pictures John Murphy flies the European flag outside his home near the border village of Forkhill, Co Armagh Reuters Brexit threatens life on the Irish border: in pictures Potter Brenda McGinn stands outside her Mullan, Co Monaghan, studio – the former Jas Boylan shoe factory which was the main employer in the area until it shut down due to the Troubles. ‘When I came back, this would have been somewhere you would have driven through and have been quite sad. It was a decrepit looking village,’ said McGinn, whose Busy Bee Ceramics is one of a handful of enterprises restoring life to the community. ‘Now this is a revitalised, old hidden village’ Reuters Brexit threatens life on the Irish border: in pictures Union Flag colours painted on kerbstones and bus-stops along the border village of Newbuildings, Co Derry/Londonderry Reuters Brexit threatens life on the Irish border: in pictures Grass reflected in Lattone Lough, which is split by the border between Cavan and Fermanagh, seen from near Ballinacor, Northern Ireland Reuters Brexit threatens life on the Irish border: in pictures Donegalman David McClintock sits in the Border Cafe in the village of Muff, which straddles Donegal and Derry/Londonderry Reuters Brexit threatens life on the Irish border: in pictures An old Irish phone box stands alongside a bus stop in the border town of Glaslough, Co Monaghan Reuters Brexit threatens life on the Irish border: in pictures Billboards are viewed from inside a disused customs hut in Carrickcarnon, Co Down, on the border with Co Louth in the Republic Reuters Brexit threatens life on the Irish border: in pictures Seamus McQuaid takes packages that locals on the Irish side of the border have delivered to his business, McQuaid Auto-Parts, to save money on postal fees, near the Co Fermanagh village of Newtownbutler. ‘I live in the south but the business is in the North,’ said McQaid. "I wholesale into the Republic of Ireland so if there’s duty, I’ll have to set up a company 200 yards up the road to sell to my customers. I’ll have to bring the same product in through Dublin instead of Belfast’ Reuters Brexit threatens life on the Irish border: in pictures A disused Great Northern Railway line and station that was for customs and excise on the border town of Glenfarne, Co Leitrim Reuters Brexit threatens life on the Irish border: in pictures Alice Mullen, from Monaghan in the Republic of Ireland, does her shopping at a former customs post on the border in Middletown, Co Armagh. ‘I’d be very worried if it was a hard border, I remember when people were divided. I would be very afraid of the threat to the peace process, it was a dreadful time to live through. Even to go to mass on a Sunday, you’d have to go through checkpoints. It is terribly stressful,’ said Mullen. ‘All those barricades and boundaries were pulled down. I see it as a huge big exercise of trust and I do believe everyone breathed a sigh of relief’ Reuters Brexit threatens life on the Irish border: in pictures A bus stop and red post box stand in the border town of Jonesborough, Co Armagh Reuters

This nice salt-of-the-earth chap has every right to these opinions. At the time, Vote Leave, for whom Daniel Hannan was a hugely influential strategist, was stoking up anti-Muslim sentiment, scaremongering about Turkey joining the EU.

That since the referendum, he has liked to tweet things like, “If someone tells you the referendum was all about immigration, you are almost certainly talking to a Remainer,” is a noble attempt to find some way to sleep at night, even if it does involve not reading the replies.

But the reality is much worse than Hannan and co think. It’s long been known that there is no configuration of free trade deals to be had outside the EU that comes close to adequately replacing what will be lost in trade by leaving the single market.

Even if there were, it would involve trade deals with, for example, India, who have made abundantly clear that any free trade deal would require improved UK visa rights for Indian nationals.

And who would have to grant those? That’s right, Theresa May, the very same person who fought to effectively veto an EU/India trade deal necessitating improved visa rights. She was in the middle of driving xenophobic vans round London, showing there were absolutely no limits to which she would not go to bring down immigration.

And who can blame her? Even now, people who are not demonstrably mad try to make the case that the Brexit vote was about a pivot from the EU back to the Commonwealth.

And this is happening in the midst of arguably Theresa May’s biggest humiliation as Prime Minister – the systematic humiliation of elderly ethnic minority British pensioners who were invited here as children.

Of course, the temptation is to blame Theresa May personally for Windrush, and such a course of action would not be wholly unjustified. But it cannot be ignored that democratic politics is subject to market forces. If there were no anti-immigrant sentiment alive and well in Britain today, it is hard to see why, while Theresa May was busy setting up her “hostile environment” , the merchandise section of Ed Miliband’s Labour Party website had “controls on immigration” mugs for sale on it.

'People's vote' Brexit campaign group fronted by MPs Caroline Lucas, Anna Soubry, Chuka Umunna and Layla Moran calls for referendum on final EU deal

There is to be a Commons vote on Thursday over continued membership of the customs union, but given the Conservatives are expected to lose, they have already said they will not take part in it. Indeed, one of the more surrealist emblems of the return of “parliamentary sovereignty” has been the consistent Tory abstention from it.

In advance of the debate, the likes of Sajid Javid have said that the EU referendum gave “clear instructions to politicians” on leaving the customs union. Again, no one doubts the sincerity of Javid’s conviction but that palpably did not happen. Arguably the most reckless aspect of David Cameron’s referendum was that it was designed only for a Remain vote, for everything to remain the same. It offered no contingency for how to proceed through the many pathways of Brexit, no method for any mandate to express itself. But if Javid thinks a Brexit vote was a clear instruction to say no to immigration from Poland, Romania, France, Germany and the rest, and yes to free trade with India and the rest of the commonwealth, and all the extra immigration that will inevitably have to come with it, then it’s worth taking a walk down Barnsley high street.

The process of extracting meaning from mass democratic events, of interpreting “what the public are really saying” is among the most depressing aspects of political analysis. The electorate are saying millions of things, using millions of blunt instruments to arrive at a crude vote. But it nevertheless cannot be ignored that a year ago, Theresa May made clear her negotiating position – leaving the single market, leaving the customs union – and she asked the country to “strengthen my hand in the negotiations with Brussels.”

That request ended with her unable to govern without the backing of a fringe Northern Irish party, who won’t accept any difference in status between Northern Ireland and the rest of the UK, and won’t countenance any return to a hard border either. That is reality.