Anyone caught carrying a blade will be prosecuted and will not be allowed to escape with a caution under a crackdown on knife crime promised by Gordon Brown.

Police must prosecute those of any age who are found in possession of a blade in areas where knife crime is high. London, Liverpool, Birmingham and Greater Manchester are among the 12 priority areas.

Mr Brown is bringing forward a Violent Crime Action Plan which will be announced by Jacqui Smith, the Home Secretary, early next month.

The Government may also introduce an outright ban on some hunting knives.

In an interview with The Sun today, Mr Brown says: “You cannot be casual or cool about knives. Society cannot cope with people carrying guns and knives and threatening to use them.

“There are boundaries you cannot cross and one is this country’s zero tolerance on knives. It is neither cool nor does it make you safer to carry a knife. We must ease people’s fears. They deserve freedom from fear about their safety on the streets.”

Faridon Alizada, 18, from Bexley, southeast London; Bradley Whitfield, 16; and Nassirudeen Osawe, 17, were all murdered recently in stabbings.

Mr Brown wants the 12 worst-hit areas to receive a zero-tolerance message. In the interview he says: “It is completely unacceptable to carry a knife or a gun. We are to step up action. Where the police have previously been cautioning people there now has to be a presumption of prosecution. We will charge, not caution.”

The Prime Minister also expresses concern at computer games that show characters surviving being stabbed, but he cannot ban them. “I am very worried about video and computer games,” he says. “The industry has some responsibility to society and needs to exercise that responsibility.”

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