He said that trying to debate with both left-wing and right-wing views had become "totally unproductive" and "frankly just completely and utterly depressing".

In a statement stretching to more than 1,100 words, he said: "I find myself constantly engaging with people denouncing my motives while sending abuse. And my friends ask: What are you doing? Why are you wasting your life on this nonsense? And they're just right.

"Added with the usual far-right extremists sending ever more creative descriptions of how they're going to torture and murder me, I'm no longer convinced social media is as useful a tool for political debate and discussion as it once was.

"I know the obvious responses to this. Put your violin away, stop pitying yourself. Get a thick skin. You put your views out there, expect to get attacked. That's how this works.