Appearing on the BBC comedy show, Have I Got News For You the Tooting MP, Sadiq Khan dismissed supporters of leaving the European Union as "xenophobes".
Peter Whittle, UKIP's candidate for London Mayor said, "Writing off what may well be a majority of the population as xenophobes just shows how Khan isn't capable of leading our great city. He holds millions of Londoners in contempt.
"Believing that Britain should be free and that London can and will thrive outside the European Union is a question of aspiration, and something that can engage all Londoners. It is not something that deserves the insults and incomprehension of people like Sadiq Khan."