It is easy to be complacent about the threat of a resurgent far right. The most bloody and grotesque examples of fascism have not been found in Western Europe for more than seven decades now. The advance of liberal democracy, tolerance, racial, gender, sexual and religious equality has been real and awesome. Today important decisions in Europe are made by national leaders over warm scallop salad at the European Council table, not drawn up in force after years of violence.

However, much of the progress we made in the second half of the 20th century, and in the early part of the 21st, is under threat. In Britain, Europe, the United States and elsewhere, an extreme, populist right is gaining currency and, increasingly, power. Extreme right parties are polling at 10 per cent in Spain, 20 per cent in France, and – if you combine UKIP and the Brexit Party – 25 per cent in the UK. In Hungary, Poland, Italy and the United States, the populist right already have the keys to power.

These movements are not calling for genocide, the imprisonment of their political enemies, or expansion into foreign territory. However, they are demanding politicians obey a vague, undefinable “will of the people”. They are creating the false narrative of a betrayal by foreign “elites” (cue Brussels bureaucrats). At home, they are scapegoating and demonising migrants (think of Nigel Farage’s “Breaking Point” poster), while harking bark to a deeply nostalgic vision of ethnically hierarchical past, with calls for “Empire 2.0”. They are attacking the truth, while denying the authority of experts and intellectuals (“people in this country have had enough of experts,” in the words of Michael Gove). They are using the demagogic tactic of repeating lies so often that people believe they are – or at least could be – true (“No deal is better than a bad deal”). At their worst they even threaten violence and unrest (“I will be forced don khaki, pick up a rifle and head for the front lines,” Nigel Farage).

Even if we do not yet have full-blown fascism, all are tactics that Madeleine Albright and other scholars have identified as deeply fascistic. In the United Kingdom, those pushing this agenda range from street thugs at Tommy Robinson protests, to an overtly Islamophobic UKIP, to Nigel Farage’s Brexit Party. As Paul Mason has written, these political groups share out their work at different levels. And while the ERG pulls the Conservative Party to the right from within, the Brexit Party does the same from the outside. Boris Johnson’s transition from liberal Tory, to someone who has had private talks with white supremacist Steve Bannon and is happy to demonise Muslim women as “letterboxes” and “bank robbers” for electoral gain, shows how successful these elements have been. Meanwhile UKIP, those associated with Tommy Robinson and online hate groups normalise the worst elements Islamophobia and intimidation on our streets.

In On Totalitarianism, Hannah Arendt, the Jewish American political theorist who fled Nazi Germany, presciently warned that fascism relies on “more respectable forms, until the whole atmosphere is poisoned with totalitarian elements which are hardly recognisable as such but appear to be normal political reactions or opinions”.

Leading figures within the hard right takeover of a once noble Conservative Party are facilitating exactly this. When ERG chair Jacob Rees-Mogg tweets a speech by the parliamentary chair Alice Weidel of the far-right Alternative für Deutschland, at the very least he signals that this party holds a view worth listening to. (Editor’s note: Rees-Mogg has since denied that he supports the party’s platform.) As I told Andrew Marr on Sunday, elected mainstream politicians have always provided “cover for the thugs on the ground”.

It hardly needs to said that there are several reasonable reasons to want to leave the EU, from both the left and the right. And many within the Conservative Party are also appalled by the steady widening of the Overton Window. Former Deputy Prime Minister Michael Heseltine has spoken out against the anti-elite and anti-immigrant politics which has a “basic, chilling appeal for people” as it did in the 1930s. The same parallels are being drawn in the United States too, where Democratic Presidential candidate Beto O’Rourke made the point that Donald Trump’s decision to describe immigrants as “animals, not people” and an “infestation” is more appropriate language for a leader in the “Third Reich.”

These shocking analogies are necessary to draw because of the deadly seriousness of the extremes this new right encourages and legitimates. Ethnic minorities and immigrants are always the first to feel the consequences of the extreme right. If you are a minority in Britain, you are feeling vulnerable in a way that you did not a decade ago. The number of hate crimes directed at people because of their religious beliefs rose by 40 per cent between 2017 and 2018. Just last week a man in Luton pleaded guilty to a charge of racially aggravated intentional harassment against myself and other MPs. Women too, are often the subject of abuse and harassment. Earlier this month, we learned how Neo-Nazi Jack Renshaw had plotted to kill my Labour colleague, Rosie Cooper.

But we should all be worried. In 2018, 13 supporters of the white supremacist National Action Group were convicted under terrorist legislation in Britain, mirroring trends across Europe, where the number of right-wing extremists arrested doubled between 2016 and 2017.

We all have a duty to call out, de-legitimise and debunk everyone who makes links with, or provides cover for, the extreme right. Our media must sharpen up so that it is able to properly oppose it, rather than aid, abet and unthinkingly promote. History teaches us clearly that we cannot afford to appease, or give fascism the benefit of the doubt.