Britain:Boris Johnson will officially launch his campaign to become the Tories' candidate for mayor of London today.
The colourful Conservative MP for Henley will be fighting for the right to take on Labour's Ken Livingstone in next year's poll.
Yesterday Mr Johnson urged the public to "take a risk" by personally tackling thugs causing trouble on the streets - advice at odds with the police.
Despite fear of violent crime running high in cities after a series of fatal attacks, the MP said the chances of getting stabbed while challenging troublemakers were "microscopic".
Police, however, said people should call them if they saw criminal behaviour, rather than risk "escalating" the situation.
Mr Johnson said: "What drives me mad is when you see some kids behaving badly at the top of a double-decker bus, but no one has the guts to intervene because they're scared.
"If one person speaks up, they are seen as brave, but everyone else keeps quiet. What if everyone together on that bus were to intervene? We need a bit more willingness."
Asking in an interview for the News of the Worldwhether people should be worried about getting stabbed, the Tory front-bencher replied: "Your chances of getting stabbed are very small. You know and I know that your chances are microscopic."
He said it drove him "wild" that individuals who did step in often got into trouble with the law themselves.
"You have to stamp out this kind of political correctness, and tilt the balance back in favour of the active citizen taking a risk, not just on their own behalf, but for their whole community."
Last month, father of three Garry Newlove, 47, died after allegedly trying to remonstrate with teenage vandals near his home in Cheshire.
Evren Anil, 23, with a first-class degree in computer science, died from injuries sustained while confronting youths who had apparently thrown litter through the window of his sister's car in south London.
A police spokeswoman said: "The police advice has always been not to step in and be a 'have a go hero'. You should contact the police. You have to be aware that things can escalate, and are you in a position to defend yourself?"
Mr Livingstone said Mr Johnson failed to address the real issues. "The central issue to fight crime in London is to increase police numbers and provide the Met with adequate resources," he added.
- (PA)