David Lammy has called on Parliament to defy the result of Britain's EU referendum.
The Labour MP for Tottenham called on fellow politicians to "stop this madness".
He said in a statement: "Wake up. We do not have to do this. We can stop this madness and bring this nightmare to an end through a vote in Parliament. Our sovereign Parliament needs to now vote on whether we should exit the EU.
"The referendum was an advisory, non-binding referendum. The Leave campaign's platform has already unravelled and some people wish they hadn't vote to leave.
"Parliament now needs to decide whether we should go forward with Brexit, and there should be a vote in Parliament next week. Let us not destroy our economy on the basis of lies and the hubris of Boris Johnson."
Nigel Farage responded by tweeting: "I'm sure that will drive more Labour voters to UKIP."
A petition calling for a second EU referendum is proving so popular that the website has crashed.
People are invited to share alleged racism or xenophobia stories after Brexit vote to highlight "need for a plan to tackle" social effects.
Time for Project Let's-Make-the-Best-of-it.