For the first time in our history, we have a prime minister whom the far right regard as their leader. Last Saturday, far-right thugs at a demonstration in Westminster lunged at remainer and leftwing activists as they chanted, “We’ve got a lamppost just for you” and, “We love you, Boris”. The jailed fraudster and thug Tommy Robinson has declared, “We back Boris”, commending him for taking on Tory rebels and Labour “traitors”, while one of his key allies has promoted a video clip featuring Johnson with his thumbs up, captioned “The people’s prime minister” and “Parliament vs the People”, and accompanied by a football stadium-style chant of “Boris for England!”

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While Margaret Thatcher whipped up fears of Britain being “rather swamped by people with a different culture”, and held out the “prospect of an end to immigration”, the National Front – the dominant far-right movement of the time – never saw her as one of its own. If Johnson is privately concerned about becoming the pin-up for a resurgent far right, he has shown no signs of it. Instead, he and his co-prime minister, Dominic Cummings, casually play with matches, even though they know that Britain is a tinderbox.

The far right “see themselves as the shock troops of Brexit now,” as Hope Not Hate’s Matthew McGregor puts it. That self-perception must be challenged: when media outlets describe these thuggish extremists as “pro-Brexit activists”, they not only insult millions of leave voters who abhor their perverse ideology, they also confer a legitimacy the far right otherwise lacks. Just as the Eurosceptic Tory right saw Brexit as something bigger than reconfiguring Britain’s relationship with the EU – a blunt instrument in a cultural counter-revolution – the far right also spot an opportunity. For Robinson and his supporters, the goal is nothing less than driving out of public life those they regard as “traitors” – including anyone espousing any sort of progressive politics.

He and his co-prime minister Dominic Cummings casually play with matches, even though they know that Britain is a tinderbox.

Outside a Brexit party rally in Kensington, west London, on the eve of the European elections, an angry crowd shouted that Nigel Farage’s movement would remain “until you’ve gone away … the Guardian class, the whole political class”. When Saturday’s far-right mob plotted to charge a leftwing rally, this grand purge of “traitors” – through thuggery and intimidation – was what they had in mind. The murder of Jo Cox by a far-right terrorist, who later bellowed, “Death to traitors, freedom for Britain”, should have led to a national reckoning; instead it was followed by three years of media outlets screeching about “saboteurs” needing to be crushed and “enemies of the people”. Those responsible aren’t naive. They understood the political consequences – specifically, fuelling and providing legitimacy for far-right extremists – but they simply did not care.

Johnson and his entourage know that there is an emboldened far-right movement who are, in McGregor’s words, “encouraged by the language of betrayal”. The “stab in the back” narrative – blaming the failure of a grand national project on domestic subversion and treachery – has always underpinned the far right, and Theresa May’s failed promises of “no deal is better than a bad deal” and Brexit by 29 March have only fuelled them.

If the Tory Brexiters are the “suits” doing the work in parliament, the far right see themselves as the “boots” on the streets: the self-appointed enforcers of an endangered national-conservative revolution. The boots have now swung behind what was supposed to be Britain’s mainstream centre-right party.

Facebook Twitter Pinterest Boris Johnson: ‘Does the sight of tanked-up far right thugs chanting your name in central London not give you pause for thought?’ Photograph: Murdo MacLeod/The Guardian

This development should be an alarming warning for Johnson and Cummings. When you assail opponents for backing a “surrender bill” or denounce them as “collaborators”, as Johnson has done; when you paint a picture, in primary colours, of “parliament versus the people” – as though a den of traitors is at war with the populace – are you really oblivious to the consequences? Does the sight of tanked-up thugs chanting your name in central London not give you pause for thought? A far-right street movement is real, serious and determined, and our rulers cannot dismiss it as irrelevant. Already, individuals with public platforms who hold unapologetic progressive opinions know that to express them is to put themselves and their loved ones at risk.

The danger is that recent events foreshadow something much uglier. In the last election, Labour members were demonised as terrorist supporters and Britain-haters – tropes embraced by the far right. This time, the boots on the street are stronger, the political context more vicious and defined by increasingly irreconcilable divisions. In such a setting, what will an even uglier campaign waged by the Tories and their media outriders mean? Even before Jeremy Corbyn’s team was surrounded by far-right activists – yelling “traitor” and “We love you, Boris, we do” – in Salford last week, members of his operation fretted about the rising security threat.

To be blunt, it is likely that more people will be hurt. When that happens, we can expect Donald Trump-style talk of “both sides” – and “what about the left and their own inflammatory rhetoric?” Toxic attempts to muddy the waters are belied by the facts: leftists have not sought to hurt, let alone kill, Conservative activists or MPs, while a global far-right movement has slaughtered socialists, Muslims, black people and Jews, from Norway to Yorkshire. The far right can only ever be defeated by a non-violent protest movement – but their enablers must be confronted, too.

To repeat for the benefit of our prime minister: a thuggish far right is real and dangerous, they treat you as their pin-up and they are emboldened by your rhetoric. You will be held accountable for whatever they do from here on in.

• Owen Jones is a Guardian columnist