A member of the Question Time audience shocked viewers when he suggested those who commit knife crime should be “exterminated”.
He began his contribution by speaking about stronger punishment for those who carry knives – which many in the audience applauded.
But his more shocking suggestion drew gasps from many.
“Don’t forget it is a particular breed of human being who can repeatedly put a knife into another person and those people should be dealt with like the cancer they are and exterminated.”
Others were heard to comment “wow” and ask “what breed is that?”
Those watching at home expressed their outrage on Twitter with many comparing the contributor to the daleks in Doctor Who.
The panel, which included shadow home secretary Diane Abbott and Tory MP Kwasi Kwarteng were asked whether stop and search should be increased.
It comes after the fifth death in six days in London from knife crime.
While many in the audience talked about the lack of youth resources and the success of the public health approach taken in Glasgow, the outspoken man told the audience in James Allen’s Girls’ School in Dulwich that the debate had mistakenly ignored the issue of punishment.
He said: “I think it’s really disappointing that we’re having yet another hand-wringing debate without a single mention of the concept of punishment.
“I know I’m probably being very old-fashioned but punishment does actually work – even in Glasgow it worked.
“And what happened in Glasgow is they tripled the average sentence for going round with a knife.
“They tripled it from four months to 13 months.
“Imagine how quickly we could turn things round if instead of 13 months it was 15 years – and that’s for people who carry knives.”
The panel did not respond to the “exterminate” comment.