"Johnson made promises he never intended to keep in a campaign he never thought he

Post-truth politics is driving us mad

Post-truth only recently entered the political lexicon, but the trend it describes has been around for some time. It was there in the build-up to Iraq, or when then-home secretary Alan Johnson sacked the chair of the Advisory Council on the Misuse of Drugs, or when George Osborne pursued a deficit reduction strategy identical to the one he'd branded dangerous when it was proposed by Alistair Darling.

Since New Labour, public relations have taken precedence over reality. This new period is just a continuation of that theme, to the point where reality is not just overruled, but made effectively irrelevant. Donald Trump is the obvious example. It simply doesn't matter whether what he says is true or not. He doesn't care, the press don't care and his supporters don't care. It's possible the US electorate doesn't care either. We'll find out in the autumn.

The same happened in the EU referendum. Leavers promised the moon on a stick: less immigration, but also maybe more. All the economic injustices fixed. Less tax, but more spending. Total control over borders and money and other countries and no sense whatsoever that the reality of politics includes compromise and the balancing of competing domestic and international interests.

But that at least was an election campaign. We are used to election campaigns containing promises which we suspect won't be kept. The depressing spectacle of Nigel Farage, Iain Duncan Smith and Daniel Hannan suddenly retreating from promises which had been made was flabbergasting, but ultimately par for the course.

What's more troubling is that the post-reality politics are continuing now we're outside the campaign. Today's Sun demands Boris Johnson follow five principles in his negotiations with the EU.

The most important is demand four: 'We will trade freely in Europe single market'. Membership of the single market means you accept the regulations which govern it and freedom of movement. That's what makes it a free market: regulatory equivalence and freedom of labour as well as capital. So it's strange to find the Sun also demand that 'British laws will trump Brussels edicts' and 'immigration will be on OUR terms'.

On a policy level, it's insane. It's not even the start of a negotiating position. It's really not much more grown up than a child screaming at its parent. And it is deeply shaming to think that European leaders would be looking at proposals like these and wondering whether they even have a negotiating partner who can be addressed on equal terms.

We're turning ourselves into a clown nation. One can't even say that our referendum decision was misjudged but principled. It was based on lies and muddled nonsense like this.

But get past the meaninglessness of the proposals and they highlight a very worrying psychological trend, which has afflicted many leading Brexiters in Westminster and Fleet Street. They seem to have no conception of other people existing. The Sun demand is that we get all the benefits of the single market system without the costs (these are perceived costs by the way – freedom of movement is actually essential to our economy, but there's no point going into that here). It’s like going into a shop and demanding all the things in it but refusing to pay.

Brexiters are exhibiting the same level of psychological development as a stubborn child. And that type of mentality is visible everywhere, in the constant angry shouts that we can do what we like, we don't need foreigners ordering us about anymore, in the vague appeal to we're-British-we'll-be-fine we saw used as the response to every question raised by Remainers.

This is not a sign of strength. It's a sign of weakness. Strong countries do not pretend to have powers beyond those they have, they do not retreat into cocoons in which they are the only pertinent humans living on the planet. This is a fantasy for people who are terrified, not an expression of strength from people who are confident. It's gunboat diplomacy with no gunboats.

If this were just restricted to the press, it would be a particularly pernicious example of their standard operating procedure. But the scary part is Johnson does not seem to be adapting to political reality either. His piece for the Telegraph on Monday engaged in exactly the type of irrational bluster the Sun is demanding as a negotiating position today. We'd have the single market and Brits could travel wherever they liked – but there'd be no reciprocal relationship.

His friends (ie: Johnson) have now retreated from that, by which we can conclude that he means the freedom of movement part. And the only way he can do that is by removing us from the single market. That would be the most economically damaging decision ever knowingly taken by a British government. It would be tantamount to actively going against the national interest.

And for what? Because we 'perceive' immigration to be a problem, despite the overwhelming evidence of economic benefits it brings. Because Johnson made promises he never intended to keep in a campaign he never thought he'd win. For that reason we are going to destroy the economy of this country and the quality of life of the people in it.

That's where post-truth politics has got us. We've clearly gone mad.

Ian Dunt is the editor of Politics.co.uk

The opinions in politics.co.uk's Comment and Analysis section are those of the author and are no reflection of the views of the website or its owners