Britain already has knife control.
Really.
“The law already prohibits the possession of offensive weapons in a public place, and the possession of knives in public without good reason or lawful authority, with the exception of a folding pocket knife with a blade not exceeding three inches.”
http://news.bbc.co.uk/2/hi/health/4581871.stm
Really.*
No wonder Eric Idle wanted to know how to defend himself against a point-ed stick! That's all you'll be left to defend yourself with.
Have rocks been outlawed in England yet?