With one year to go until Brexit, it's worth reflecting on some other salutatory anniversaries. It is exactly 20 years since the last military conflict on UK soil finally ended with the signing of the Good Friday Agreement in Belfast. It is 50 years this month since Enoch Powell's “Rivers of Blood” speech, the definitive statement of anti-immigrant paranoia. It is touch and go whether fear of the latter will destroy the former, as Britain slouches toward the exit of European civilisation.

There has been some dispute over whether immigration really was the "Big Issue" for Brexit voters, but no one can deny it was a very large factor in their thinking. The very phrase “take back control” contains within it a dog whistle for ethnic nationalism and xenophobia. It was about making Britain for the British (at least south of the Border – the issue was rather more complex here where the vote went the other way). The irony is that while predominantly white EU migration has fallen sharply, non-white immigration from non-EU countries has increased, and is set to rise further. Alf Garnett may not be amused when he finds out that Brexit means more black and brown faces. Brexit hasn't even fulfilled the nastier objectives of leaving the EU.

This rather sums up the whole misconceived, misanthropic, misunderstood project. As does the fact that those pro-Brexit constituencies in the post-industrial north of England are the ones likely to be hit hardest by leaving the single market, while the prosperous, pro-EU south of England is expected to escape largely unscathed. The politics of Brexit are all a*** over tit, as Mr Garnett might have put it.

The British Government persists with its oxymoronic claim that there needn't be a land border in Ireland even as it creates one. Yet, that’s surely what is meant by taking back control – “of our money, our laws and our borders”, as Theresa May insists on putting it, as if we were expelling a bunch of thieves who had evaded security. The whole Brexit project reads like an exercise in cognitive dissonance. Not even its advocates seem to know what Brexit is for any more.

Britain's trade policy is still premised on the fantasy that, after Brexit, nothing will change. That the EU will allow Britain to have exactly the same trading relationship that it currently has with the European Single Market, even though the UK has left it. Meanwhile, we will get on with the business of forming those new trading relationships with all those countries who are gagging for it like, er, Saudi Arabia – which really rather likes buying our arms. Not even the Government tries to hide the reality that Brexit will come at an economic cost.

The PM’s whistle-stop tour of the “provinces” last week sought to convince the nation that that we’re getting on with the business of Brexit whatever it means for business. Britain will just be, well “different” – get used to it, that was the message. The PM has been basking in the reflected glory of her propaganda war with Vladimir Putin and this trip was really intended as a kind of victory lap. The press has stopped talking about the “Maybot” being a basket case Prime Minister, who can’t string two policies together and is hiding under her desk in Number 10. But her improved standing among the commentariat doesn’t alter the reality that Brexit is breaking bad.

May insisted last week that leaving the EU has brought “our precious union” close together. It has done precisely the reverse, not just by erecting borders on the island of Ireland but by undermining the devolution settlement in Scotland and Wales. Brexit confusion may have killed off any repeat independence referendum in Scotland for the time being, but there’s precious little evidence that support for the Union has been enhanced over the past year. The loss of European citizenship is deeply resented in Scotland, and the ham-fisted power-grab in the EU Withdrawal Bill has demonstrated just how fragile the powers of the Scottish parliament really are.

The UK government knows that, strictly speaking, all powers not reserved to Westminster are Holyrood’s by default – but this is no time for legal niceties. The UK internal market must be made whole again, and this means that the key powers over environment, food standards, animal welfare and so on will have to be set centrally for the whole UK. This is not so much a Westminster plot to roll back devolution, as an inevitable consequence of Brexit, like the Irish border. Ministers and civil servants lack the time or the will to work out any solution other than regulatory centralism, so they endeavour to hold two contradictory propositions: that devolution will be enhanced even as its founding principle is abandoned.

This is symptomatic of a depressive malaise that has struck the entire British political class, not just the government and Whitehall. It is impossible to make sense of Labour's position on the EU. One day front bench spokespeople are setting “six tests” for Brexit, and the next saying it's “inevitable” and that Labour will vote for it anyway. Labour are supposedly in favour of a customs union – not THE customs union, but another one that is yet to be negotiated. This is the same as the UK government’s own “have your cake and eat it” approach, but we are told it is different because, well, it’s Labour, and therefore must be.

Yet on the face of it, there is everything for an opposition to play for. The EU Withdrawal Bill has been mauled in the House of Lords, and there will be a string of amendments appended to it when it returns to the Commons, including one on remaining in the EU Customs Union which is almost certain to pass. MPs also have the right to a vote on the Brexit deal when it is finally concluded in the autumn. You would think an imaginative opposition might be able to use this to undermine the government's entire Brexit project, and lead the country back into the single market. But then you realise that the UK's main opposition party clearly doesn't want to undermine Brexit – or is at least in two minds about doing so. When Brexit day finally dawns, in one year's time, the project will have been largely destroyed intellectually, but no-one will be able to stop it happening. We'll be like innocent bystanders to our own car crash.

Why has there been an absence of opposition to this momentous change which almost no-one thinks is worth while? Well, possibly because there seems very little change of heart among Brexit voters. There is a small shift towards remain, and they’re clearly unimpressed by the negotiations, but there has been no pro-EU sea change, or even a serious case of buyer’s remorse. This is probably because the economic arguments have always been secondary to the deeper cause of Brexit, which is essentially an emotional yearning for national revival, not dissimilar to Donald Trump’s Make America Great Again. It is a mission statement for the masses – an appeal to atavistic instinct. Unless the pro-Remainers find a similar gut appeal, then Britain will go grumpily into the Brexit wilderness in one year's time, and spend the subsequent decades trying to limit the damage.