London mayor Sadiq Khan has 24-hour police protection following repeated threats on social media.
Mr Khan, who was MP for Tooting before defeating Zac Goldsmith to succeed Boris Johnson as mayor, said levels of abuse had risen since the 2016 Brexit referendum.
The Times reported that City Hall referred 17 cases to the police in a three-month period last year and 237 threats were made on social media.
Mr Khan told the paper's magazine that the abuse had gone from "name-calling, trolling and threats to terrorism".
He said: "It can't be right that one of the consequences of me being the mayor of London and a Muslim in public life is that I have police protection.
"The referendum campaign allowed things to come to the surface and normalised things that should not be normalised."
The Labour politician said there had been a rise in Islamophobia, anti-Semitism and homophobia, but that he did not place the blame for this at the door of Leavers.
However, he told the magazine: "It starts with name-calling, it can lead to criminal damage and graffiti (and) ultimately to the situation where Jo Cox is murdered or a terrorist can come to London and try to divide communities."