There is an ugly authoritarianism brewing on the left of British politics, one that reared its head during the anti-austerity protests on 4 October at the Conservative Party Conference in Manchester. Journalists and delegates have been spat at, pelted with eggs, intimidated and branded as scum.

It is not the first party conference to be picketed by protesters and it will not be the last. Indeed, the day that a meeting of a sitting government – not least one as divisive as David Cameron's Conservatives – does not attract a healthy turnout of angry protesters would be as disappointing as it would be worrying: evidence that either apathy or outright resignation had finally won the day in British politics.

It has been argued in these pages already that the majority of those who are manning the barricades in Manchester are non-violent, and the heavy presence of the Disabled People's Action Committee (DPAC), NHS workers, and teachers is understandable given the cuts to health and education.

As our columnist Abi Wilkinson wrote this week, to tar these hundreds of concerned demonstrators with the same brush as a minority of thugs is unfair. But it is equally wrong to ignore them.

Outside the Conservative Party Conference, delegates were warned not to wear their passes visibly lest they be abused or pelted with eggs. Just to hammer this home: people exercising their right to not agree with the left were warned to conceal their views because of fears they would be attacked. That is what we have come to in this country. That is not democracy - it is mob rule and we should fear it.

Democrats do not spit at journalists or call those with views that don't align to their own 'scum'. They don't intimidate people who don't agree with them or cast aspersions on the motives of journalists that dare to question their stance on issues. Equally – as we saw in recent weeks – they don't besiege stupid hipster cafes in Shoreditch with flaming torches, try to break windows and frighten young families.

You know who does these things? Fascists.

We cannot ignore these individuals any more than we can ignore what they represent: a frightening, anti-democratic shift on the left that has increased with the election of Jeremy Corbyn as Labour leader. That campaign and its aftermath saw numerous cases of intimidation and abuse by keyboard warriors against those who disagreed with Corbyn or his policies. The events in Manchester reflect this trend in the real world.

There was a growing anti-austerity movement prior to Corbyn, of course, but the radical element that the egg-throwers, scum-shouters and journalist-spitters represent has undoubtedly gained prominence in the weeks since his election as leader. The Corbyn movement has led to an enfranchisement of many young voters, this cannot be denied, but it has also given succour to the less salubrious elements on the radical left.

That these authoritarian voices have coalesced around Jeremy Corbyn is ironic really, given his record as a champion of civil liberties in Britain over the past 30 years. Corbyn defied his own party and voted time and time again against legislation by New Labour that would have eroded personal freedom in Britain – including the freedom of speech. A fact that another columnist of ours, Mohammed Kozbar, highlighted last week.

It is equally ironic that those on the barricades in Manchester have so often chosen the symbols of anarchism or socialism to justify acts of violence against people who disagree with them. Or perhaps not, for isn't socialism's true weakness its inevitable descent into authoritarianism?

George Orwell wrote about it decades ago, and how many tragic examples have we seen since? The evolution from a mob that abuses and attacks its opponents on the streets for the principles they hold is not a million miles away from the mob that silences its enemies permanently. The right has never had a monopoly on fascism.

The saddest thing about all this is that the tactics of the scum-shouters in Manchester provides the Conservatives with a socialist bogeyman to hold up and say: "Here is your alternative".

This small minority will be the lasting image of the popular protests against austerity and cuts this week, rather than DPAC or those marching against the Trade Union Bill. It is a festering sore within the British left which, left unchecked, will destroy it.