Gordon Brown has responded to growing public concern over knife crime by lowering the minimum age teenagers can be prosecuted for carrying knives from 18 to 16.
The move was announced by the government this morning after the prime minister and home secretary Jacqui Smith met with representatives from the Association of Chief Police Officers (Acpo) at Downing Street.
Mr Brown's announcement comes after Arsema Dawit was stabbed to death in a block of flats near London's Waterloo station early this week.
The 15-year-old girl is the 16th teenager to die violently in the capital so far this year.
"We have to send out a message and reinforce it with immediate action. It is completely unacceptable to carry a knife," the prime minister said today.
"Young people need to understand that carrying knives doesn't protect you, it does the opposite - it increases the danger for all of us, destroys young lives and ruins families. Recent tragic events have reminded us of that."
MPs are set to hold a special 90-minute Commons debate on knife crime some time in the near future as the issue continues to dominate public concern.
The government, keen to be seen acting in response to the problem, has doubled the maximum sentence for carrying a knife to four years and spent £3 million on an anti-knife advertising campaign and
"Those who carry a knife on our streets need to know that they will be caught and should expect to end up in court. They will face tough consequences," Ms Smith commented.
Other new measures announced today include £5 million injected into areas particularly affected by knife crime, increased use of searches and more home visits to parents of those suspected of carrying weapons.
Shadow home secretary David Davis said Mr Brown's "tough talk" on knife crime is "undermined by his appalling record".
The Conservatives point out one in four offenders is currently released with only a warning or caution, while fewer than one in seven receives a prison sentence.
"Extending a failing system may make for a nice announcement but it won't fix the problem in the short term nor address the fundamental causes of violent crime," Mr Davis commented.
"This latest announcement shows he [the prime minister] has run out of ideas. This makes him part of the problem, not the solution."
Liberal Democrat leader Nick Clegg said the government should scrap its identity card plans and use the freed-up funding to pay for more police on the streets.
"There can be absolutely no justification for carrying knives at any age," he said.
"But the government must work harder to reassure youngsters so that they do not feel the need to carry weapons to defend themselves."