Saying being smacked never did you any harm is a bit like grandstanding about your uncle who died in his 90s despite smoking 60 a day. You can't be sure about cause and effect and the evidence suggests it is unusual.

The findings of a new report on the physical punishment of children are hard to argue with. An accumulation of studies show consistent patterns and convincing evidence of, among other things, damage to children's psychological well-being in childhood and adulthood and a negative impact on future behaviour.

This has long been a controversial issue. It is a message many of us are reluctant to hear. We diminish this violence against children as 'more of a light tap', tie ourselves in knots with justifications.

Yet parents can and do hit their children in a way which would be assault were they to do it to another adult in the street. It is an indefensible double standard.

Already, many parents try to avoid physical punishment, which nearly always happens in moments of anger, of lost control. Hitting someone when you are angry is a lousy lesson to impart to children and most of us know it.

Some will warn that the state should not encroach on judgements about parenting. Criminalising parents is certainly no way to improve things for them or their children and a ban should be opposed if the goal were to prosecute parents.

But a prohibition on physical punishment should be largely symbolic, accompanied by education and awareness raising and reinforcing the existing direction of public opinion.

The UK is one of only five European states to still permit smacking. Other countries have shown changing the law need not lead to unnecessary prosecutions of parents.

Parenting is one of the most difficult jobs any of us will do. Outlawing smacking, if handled the right way, could make it easier, not harder.