We've had restrictions on possessing blades in a public place for a long time. I seriously doubt any further tightening of the law is likely. Knives are too important/useful as tools for stuff other than slashing/stabbing people or animals. The legislation was originally tightened up to deal with the 'switchblade' culture amongst gangs (especially in the East End of London and Manchester's Hulme and Moss Side) and for a long time knife crime stopped being so much of a problem. It's kind of creeping back into the culture again now. Guns are also getting more common, amongst teens and gangs, but knives tend to be the weapon of choice. We do get the occassional nutter with a samurai of course.