Both platforms are accused of failing to remove abusive messages prompting prime minister Theresa May to launch an official inquiry headed by crossbench peer Lord Bew, who has begun a series of interviews in an effort to understand the apparent inaction.
Bew has likened the atmosphere of online threats and intimidation to that of Northern Ireland during the Troubles, warning that other politicians lives are at risk following the shocking of MP Jo Cox during the European independence referendum.
Speaking to The Telegraph Bew said: “For all the many failures of the British political system, we have one great achievement, which is the culture of relative civility. That’s what is at stake now, it really is. We have learnt to do politics without killing people in this country for centuries. This is something not to be neglected, it must be protected at all costs.”
Bew, who heads the independent committee on standards in public life, has been tasked with investigating press reports of harassment and personal attacks directed against candidates during the recent general election.
Both Twitter and Facebook have defended their responses, insisting that their existing policies are up to the task in hand.
In the immediate aftermath of the election May called for internet firms to stop providing terrorists with 'safe places' from which to operate online.