We were told back in the 1990s about the end of history, but no one thought to warn us about the end of truth. And yet, as 2016 drew to a close, Oxford Dictionaries named ‘post-truth’ as its international word of the year. According to the lexicographers, the term applies to a world in which ‘objective facts are less influential in shaping public opinion than emotional appeals’.

At one level, perhaps this is a fuss about nothing. It would be possible to make a convincing case that objective truth has played little role in shaping the great political events of history. Germany after 1933 was post-truth. And so was the USSR for much of its existence. Were the populations of medieval Europe prone to pogroms and religious wars because of objective facts? Or were they motivated by emotional and utterly irrational appeals?

The issue has come to the fore in the second decade of the 21st Century because we like to believe that we are governed by rationality. After all, we live in an age of constant scientific and technological revolution. So when liberal and left-wing thinkers see the public unconvinced by the sensible arguments for continuing membership of the EU, they panic. When they observe the way in which American voters are swayed by the demagogic rhetoric of Donald J Trump, they are enveloped by a sense of horror.

‘Fake news’ is also on the agenda. It was allegedly used by Putin and shady right-wing organisations to undermine the campaign of Hillary Clinton. And once again, it’s a case of back to the future. The infamous Zinoviev Letter – which sought to demonstrate the influence of the Soviet Union over the British left – was a big fake news story back in the 1920s. Plus ça change, plus c’est la même chose.

But in 2017, we feel we should be more sophisticated than our ancestors and able to sniff out bogus arguments at a distance of 500 metres. So we panic when we realise this isn’t in fact the case.

My concern at the moment is that it’s easy to take the moral high ground in the current debate and believe that the ‘post-truth’ and ‘fake’ universe is one created solely by the right.  Regrettably, the reality is rather different. A determination to ignore facts is, I would argue, just as prevalent on the left.

Look at the current dispute on Southern Rail, for instance. Members of ASLEF and the RMT claim to be fighting against driver-only operation on the grounds of public safety. But there is no evidence to back up their case. Indeed, a freedom of information request to TfL by the London Evening Standard revealed that when the Mayor’s Office removed guards on lines in the capital, safety levels improved. There were fewer instances of the doors being opened on the wrong side or outside the station.

So when the unions look for support, they do so on the basis of emotional appeal (class solidarity, gut instinct and a frustration at the overall standards of service on the railway), rather than the presentation of any objective facts.

The alternative left-wing media that has grown up around the Labour leadership and Corbyn’s cult of personality is equally detached from reality. Take The Canary, for example. Its polemical style and clear political agenda make it every bit as partial as The Daily Express or The Daily Mail. Yet it has the audacity to attack the BBC for bias and has been part of the tedious campaign against Laura Kuenssberg – a political editor who has the temerity to ask Jeremy Corbyn questions he finds hard to answer.

We almost have to pinch ourselves. In a post-truth world, the BBC can be accused of bias by The Canary. A little like Chelsea or Manchester United being criticised for their amateurism by the manager of a team in the Ryman League.

On the international stage, post-truth comes in the form of state-funded RT – the Kremlin-backed channel which rails against the MSM while boasting satellite links, plush studios, foreign bureaux and a host of advertisers. It seems to put on air anyone with an agenda and a Skype connection – from freelance journalists and offbeat academics to activists with axes to grind. One recent Op Ed piece on its website compares NATO to Nazi Germany.

When objectivity and factual analysis desert us, history tells us that the consequences can be dire. The climate at the moment in North America and Western Europe is particularly febrile. If we are to challenge the lies and distortions of Trump and Farage and Le Pen, it is incumbent on the left to play by a different set of rules. Not to create a bizarre mirror image of the right’s antics, which destroys any remaining trust in the political process.

Phil Woodford

Phil Woodford stood on two occasions as a Labour Parliamentary candidate and is a former chair of Holborn & St Pancras CLP. He currently works as a writer, trainer and lecturer and co-hosts a weekly news review show on London's Colourful Radio.