"Boris Johnson urged people to walk away if they see a crime committed rather than risk their own lives.
The London mayor admitted he would tell his own children to "look after themselves" rather than play Good Samaritan to a victim.
Just last year, he called on people to "take a risk" and tackle thugs, saying the chance of being stabbed was "microscopic".
But Mr Johnson revealed a "very nice ex-jailbird" recently warned him: "If you see a fight in the street, don't risk it, someone might have a knife."
He said: "I'm afraid that may sound like a lack of public spirit if someone is being badly attacked.
"But if I was giving advice to my kids and there was a bar brawl it would be to look after themselves.
"Everybody is shocked by the level of violence we are seeing, particularly towards young people, and we must all work as hard as we can to reverse this dreadful trend."Work hard. As in running, really, really fast. You see, Boris, this is precisely why the predators have begun to swarm. Don't think for one moment that these low lives would attack people who could cause them grievous injury, hells bells, man, thats why they're in London. They know full well that you and your frightened Bobbies will take the criminals side should push come to shove, just like liberals try to do here in America.
Cowards, you see, are not nationality-specific.