It is two weeks since the broadcast of John Ware’s BBC investigation into alleged institutional antisemitism in the Labour Party. Supporters of the current Labour leader wasted no time in beginning an online campaign of vilification against the whistleblowers who had bravely taken part. And last Saturday, one of those whistleblowers received a death threat.

This would seem a far cry from the “kinder, gentler politics” that the Labour leader once promised. How could it happen? I believe that the ‘blame’ may lie in the culture created by those groups that have hitched themselves to the Jeremy Corbyn bandwagon despite seeing the answer to Britain’s problems not in electoral politics but in revolution.

With my colleagues Siobhan McAndrew of the University of Bristol and David Hirsh of Goldsmiths, University of London, I have spent the last few months studying sympathy for violent extremism on the far left. Our report, published last Friday by the Commission for Countering Extremism, combines historical and sociological analysis of revolutionary socialist groups with a unique survey of nearly 5,000 people.

We reject the myth that left-wing violent extremism began and ended with the totalitarian rule of Stalin. Support for violence and repression can be found in the works of Lenin and Trotsky — who carried out terrible acts of their own while in power. And as for Mao, he was a despot who presided over the destruction of tens of millions of his own people. Yet these are the men whose ideas have shaped Britain’s revolutionary far left.

Today, revolutionary socialist groups stand in solidarity with the brutal and undemocratic Maduro regime in Venezuela, the genocidal Assad regime in Syria, and the indiscriminate terrorism of Hezbollah and Hamas in the Middle East. When terrorists strike against innocent British citizens, such groups respond by suggesting that the British government is somehow to blame. So it is little surprise to find that if you ask people who see themselves as “very left-wing” to identify threats to world peace, they’re more likely to point at Israel than at North Korea, and more likely to point at the UK than at Iran.

British revolutionary socialist groups do not engage in terrorism. They do not believe they have to: their strategy is the weaponisation of “the workers”, whom they see themselves as entitled to lead. But while that strategy is unlikely ever to propel such groups to power, my colleagues and I have found evidence that it may be having an effect. Our survey suggests that people who strongly agree with revolutionary (rather than democratic) socialist ideas — that is, people who long for workers to “rise up” against their bosses, who blame social problems on “the wealthy”, and so on — are far more likely to sympathise with violent extremist tactics than people who strongly disagree.

The tactics we asked about range from street violence to the use of bombs. If death threats are being issued against those who displease the far left, then we should all take note.

Dr Daniel Allington is Senior Lecturer in Social and Cultural Artificial Intelligence at King’s College London