Andrew Vine: This tirade of hate is toxic for democracy

But not for one person. A man, most probably, for whom the killing of the Batley and Spen MP in the street was not a horror, but a means of intimidating a friend and colleague of Mrs Cox, the Liverpool Wavertree MP Luciana Berger.

The death threat he sent her in the aftermath of the killing read in part that Ms Berger was “going to get it like Jo Cox did”.

The police have been informed, and maybe they will find this hateful, and hate-filled, man if they’re lucky. But most probably they won’t, if he has taken rudimentary steps to maintain his anonymity on social media.

And for Ms Berger, he is just another tormentor amongst many, since she received 2,500 abusive messages over the course of three days, among them vile anti-semitic insults and caricatures.

If using Mrs Cox’s name in an attempt to terrorise an MP marks a sickening new low, it is only another step on a terrifying descent into the violent and misogynistic abuse of female politicians via social media.

A new and unprecedented volume of vitriolic messages is bombarding MPs and their staff, with threats of rape and even murder.

There has never been anything like it in modern politics, and we need to be deeply worried about it, as are its victims.

Unless it can be stamped out, there is a real possibility that the open access to MPs that characterises our democracy will have to be limited, and people will be discouraged from standing for election.

The abuse is already having a chilling effect. Durham Labour MP Pat Glass has announced she will not stand again after receiving death threats, and former Ukip leader Nigel Farage admitted that similar threats were a factor in his decision to step aside.

The bitterness of both the battle for the soul of the Labour Party and the referendum on EU membership is a factor, but this is a trend that had already become apparent before either debate.

This has nothing to do with the normal rough-and-tumble of politics, or the occasional awkward constituent that every MP has to deal with. Nor is it about thin-skinned people letting cranks get to them.

This is about the entrenchment of aggression and violence in everyday life, and the real fear that hate or derangement will push somebody over the line into a physical assault.

Threats to kill or rape, along with instances of anti-semitism, are appearing on MPs’ smartphones and tablets with disturbing regularity, turning their Twitter feeds and Facebook pages from the means to engage directly with constituents into insidious instruments of intimidation.

No threat is too obscene to utter. In the past weeks, Normanton, Pontefract and Castleford MP Yvette Cooper called in the police after receiving threats to her children’s lives.

The Birmingham Yardley MP Jess Phillips suffered 600 threats of rape in a single evening two month ago.

The list constantly lengthens. Tulip Siddique, MP for Hampstead and Kilburn, opened a message that read: “If I could kill, you, I would.”

How seriously these threats need to be taken is shown by two convictions. One saw a man receive a suspended sentence for sending a frighteningly abusive message to Dewsbury MP Paula Sherriff, and the other resulted in a man being jailed for 18 months for bombarding Walthamstow MP Stella Creasy. A cross-party group determined to raise awareness of this tirade of abuse, Reclaim the Internet, is fighting back, but more needs to be done, and on a wider battlefront.

It is impossible – and unwise – to dismiss the torrent of abuse aimed at female MPs in particular as something that can or should be simply shrugged off and ignored.

Politicians have understandably been amongst the most enthusiastic adopters of social media. Its virtues as a means of fostering friendships and disseminating information have proved invaluable in engaging with voters.

The means of communicating instantly with constituents, inviting their views, listening to their concerns, and engaging directly in debate with them is good for politics and society.

This sort of lively dialogue on Twitter and Facebook has come to take its place in the grand tradition of how Britain does politics, with MPs – however elevated the Government positions they may occupy – accessible to the people who elect them to serve.

That openness is so valuable to politicians and voters alike, that it cannot be allowed to be perverted into a means of threatening and abusing MPs. Instant access to the influential and prominent using a smartphone has undoubtedly unleashed a dark side in a small minority of the venomous, and quite possibly mentally unstable.

Where once they might have shouted at the television, or fumed about politics with their mates in the pub, now they can reach out and feel that they are shouting directly in somebody’s face. And they are doing their utmost to be menacing.

The abusers have taken the fateful first step towards committing violence by threatening it. The more often they reach for the phone to send yet another threat, the more normalised the idea of violence becomes. The danger that poses should not be underestimated.

If we are to stamp this out, there needs to be concerted action by the police, the social media giants, political parties and the vast majority of responsible users of social media.

The vigorous pursuit of child sex abusers by police at a national level has stripped away the internet’s cloaks of anonymity and brought culprits to court. The same approach to those who seek to terrorise politicians could act as a powerful deterrent.

Those who operate the social media networks also have a crucial part to play if they are to enjoy the continued confidence of users, by immediately shutting down the accounts of the abusive and co-operating with police.

We’ve entered a new age of open dialogue with our politicians that is good for everybody and healthy for our democracy. That’s too valuable to be allowed to be perverted by threats of the most abhorrent kind.