Labour MP David Lammy has been subjected to a "barrage" of racist and threatening messages after calling for Parliament to vote against Brexit in the wake of the EU referendum.
The Remain backer and his staff were targeted after he called for a rethink on the referendum result.
Lammy, who represents Tottenham, in north London, has reported the perpetrators to the Metropolitan Police.
Tweeter @PureWhitePower wrote to him: "Go back to Africa N*****!"
The MP blocked the user and replied: "I'm not going anywhere. I was born in this country. But you and your disgusting racist views make me ashamed."
Social media users threatened to report the message to police and its author, whose profile picture is of a swastika, removed it.
One person on Facebook made an apparent threat to him while referencing Jo Cox's death.
The former London mayoral candidate previously pleaded for fellow MPs to "stop this madness" by voting down support for the UK to leave the EU in Parliament.
A former lawyer who was the first black Briton to study at Harvard Law School, David Lammy had earlier threatened to report others who had sent him hate mail to police.
One emailed him to accuse him of wanting to void a "legal and binding" vote after he encouraged people to march against a Brexit.
Lammy made the messages public, and tweeted: "Racists and trolls sending me threats and abuse: don't waste your time, I will block you and report you to the police."