Of course it would be assault

Pro child-beating factions are waving a letter from the Police Commissioner in which he says that if Section 59 was repealed, smacking your children would constitute assault and raise the possibility of criminal charges. Of course it would be - that's what happens when you remove a statutory defence. What matters, though, is whether charges are actually brought - and here the police comissioner is quite clear:

The police letter said that - as with all assault investigations - the police would consider the amount of force used and the circumstances before making a decision about whether a prosecution was required in the public interest.

"An aggravating factor in any such decision may be the fact that a child is generally more vulnerable than an adult," the letter said.

The vast majority of assaults result in no investigation and no charges being brought. While there may be a case to answer in law and enough evidence to prove it, the police have neither the time nor the inclination to pursue them. And the same will be true in cases where parents smack their children - they are highly unlikely to be prosecuted unless the assault is considered serious enough to warrant it. At the same time, prosecution is always a possibility, and that uncertainty is part of the point: to "chill" such behaviour, and thereby reduce it - just as we do for other assaults.