There were “bad people” on “many sides”: this is how Donald Trump notoriously responded to the killing of Heather Heyer, an anti-fascist protester, by a far-right terrorist in Charlottesville, Virginia, in 2017. As a debate rages over the deliberate use of incendiary language by the British right, it seems this moral equivalence has been imported.

We are told that British politics is being menaced by a general lack of civility that threatens to fuel violence from all sides, and that both left and right have an equal responsibility to dial down the rhetoric. But this deflects from the real threat: a violent far right that is emboldened and fuelled by mainstream politicians – including from the prime minister’s office – and several media outlets.

That isn’t to deny there is intemperate or aggressive language on the left, but rather to acknowledge where the threat of violence is chiefly coming from. As well as the murder of Jo Cox and other attacks, several rightwing plots have been foiled, and the police now say Britain’s fastest-growing terror threat is from the far right, which is bombarding public figures with threats of violence and death on a daily basis and harassing them on the street. Hate crimes based on race have doubled, and on religion they have increased five-fold in the last six years.

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Boris Johnson’s defenders claim that objections to his rhetoric – whether it be of a “surrender bill” or “betrayal” – are simply hypocritical oversensitivity from political opponents who are themselves not averse to hyperbolic rhetoric. But the difference is context: the far right openly sees Johnson’s language as legitimising its cause, lauding his tirades against what they describe as the “traitors in parliament”. Even his own sister has described his rhetoric as “tasteless”, and his former colleague Amber Rudd says it “legitimises violence”. That’s before we discuss how a rightwing press – which dominates Britain’s media – has popularised terms such as “enemies of the people”, “saboteurs” and “traitors”, and whipped up bigotry towards Muslims, refugees, migrants and trans people.

The far right does not represent millions of people who voted for Brexit; but they have appointed themselves the protectors of what they see as a besieged nation. They use intimidation, harassment and violence against those they deem “traitors”. And they see supposedly respectable media outlets and politicians legitimising their beliefs.

The mistake some of Johnson’s critics are making is focusing on his lack of civility – see the new Civility in Politics awards to celebrate politicians who engage in “thoughtful, reflective public debate” – rather than how his language emboldens the far right. And this creates a false equivalence. When Labour supporters critique the political records of politicians they disagree with (for example Jo Swinson’s role in the Tory-Liberal Democrat austerity government), or support the democratic deselection of Labour candidates, it is invariably treated as abusive or bullying, and placed in a “crimes against civility” box along with far-right threats of violence. It is nothing of the sort.

It is true that no political faction has a monopoly on misguided inflammatory rhetoric, but when newspapers talk of MPs engaged in “foreign collusion”, as the Mail on Sunday did yesterday, or Nigel Farage says “we’ll take the knife” to the “overpaid pen pushers in Whitehall” (he subsequently admitted that he should have said “take the axe”), they are creating an atmosphere in which the far right thrives.

We should not be debating “intemperate language”. Talk of “both sides” deflects from the real battle, which is to take on the far right and prevent its violent extremism flourishing.

• Owen Jones is a Guardian columnist