Search: Government Knives Criminals
More than 7,400 people carrying knives in England and Wales escaped with just a caution, Home Office figures showed.
They were released by Home Secretary Jacqui Smith as the Tories promised an end to the "ridiculous system of cautions".
The figures show that in 2007, the latest year for which information is available, 7,404 offenders were cautioned for illegal knife possession.
The cautions were given to knife-wielders before the Association of Chief Police Officers (Acpo) issued tougher guidance, Ms Smith explained.
She said: "Acpo guidance issued on July 22, 2008 makes it clear that anyone over the age of 16 caught in possession of a knife can now expect to be prosecuted on the first offence.
"Those under 16 can expect a formal final warning coupled with a knife education scheme to help them understand the potentially devastating consequences of carrying knives."
First time adult offenders who plead not guilty to carrying a knife, even at the least serious level of offence, should get at least 12 weeks in jail if convicted.
The 7,404 figure includes under-18s who were given reprimands or final warnings.
The figures were released in response to a parliamentary question from shadow home secretary Chris Grayling.
