Conservative leader David Cameron has called for anyone caught carrying a knife to be jailed, as another Londoner died from stab wounds on Monday.

Cameron's custodial sentence demand goes one step further than Prime Minister Gordon Brown who said last month there should be a presumption to prosecute those aged 16 and 17 caught with a knife, rather than merely cautioning them.

"We have to send the strongest possible message that carrying a knife is completely unacceptable in Britain, end of subject," said Cameron, responding to a spate of knife murders of teenagers in London this year.

"The Government should say not just there is a presumption you will be prosecuted if you carry a knife, but that there is a presumption you will go to jail.

"It is not a minor offence. There is no excuse for carrying a knife when you walk out of your door. This is about kitchen knives stuffed down the front of tracksuits.

"We're talking about mainly young people carrying knives as part of a culture. That culture has to stop."

London's latest knife victim was a man in his early 20s who died from wounds to the chest and arm in Bethnal Green, East London. A man has been arrested in connection with the death.

Deputy Metropolitan Police Commissioner Paul Stephenson has said tackling knife crime is his force's number one priority and has announced the creation of a 75-strong anti-knife squad to target "known gang members and their associates."

Two years ago Cameron softened his party's traditionally tough line on crime when he said love and emotional support were key to tackling youth crime and disorder.