I started teaching back in the days when formal and informal corporal punishment were the norm. The main difference between then and now, aside from the law, is that there has been a widespread decay of family structure in the UK, and the children in most need of learning self-discipline are the likeliest to be from families headed by immature undisciplined adults.
I do not think it is right to hit children or to issue ritualised formal physical punishment, but by the same token I do not think teachers should be required to tolerate feral behaviour.
Corporal punishment will never reappear in UK schools, but school heads should be much more proactive about expelling badly behaved pupils, and parens should be fined for allowing appalling behaviour to continue unchecked.