The Mayor of London Sadiq Khan has called for an end to online abuse against politicians.
Khan says the continual abuse aimed at politicians on social media is putting people off the industry.
"We should be encouraging minority communities to get involved in politics; we should be encouraging all young people to get involved in politics and this sort of language - racist language in particular - discourages young people to get involved in politics rather than encouraging them," Khan told ITV London.
"I'm saying unequivocally, in as clear language as possible: no more."
Khan's Conservative opponent in the next mayoral election, Shaun Bailey is another to have suffered racist abuse online.
Bailey has come under extra scrutiny since having nomination confirmed and controversial comments from his past surfaced.
Tweets sent to Bailey include "Shaun Bailey is the biggest Uncle Tom to walk the planet" and "Shaun Bailey is a lying coconut, as far as I'm concerned".
Bailey says he has had to "grown a thick skin" in order to deal with the abuse he has received.
"I've had a lot of racist abuse, in particular, since I've been involved in public life. All I would say to anyone trying to get involved is you've got to soldier on," Bailey told ITV
"What I always comfort myself with is people abuse me because they can't take on my argument, ie they see the value in my argument, so they just think they'll attack me instead but you just have to grow a thick skin which is really unfortunate."
- Watch the Late Debate on ITV at 10.45pm on Thursday 18 October