SCOTLAND'S Children's Commissioner has renewed calls for a ban on smacking, by scrapping the "unbelievable" law that allows a defence of justifiable assault for parents who hit their children.

Tam Baillie, whose second and final term of office ends on May 17, said the failure to see the law changed on the physical punishment of children was his greatest regret about his eight years as Scotland's Commissioner.

Under section 51 of the Criminal Justice (Scotland) Act 2003 the defence of ‘justifiable assault’ is available where it is claimed that an act against a child was a physical punishment carried out while exercising a parental right.

Attempts to change this as part of the 2014 Criminal Justice bill have failed. As a result Scotland along with the rest of the UK is among only five European countries which have yet to commit to giving children equal protection from assault, Mr Baillie said, adding: "We are now absolutely in the minority of countries in Europe on this."

Lithuania banned the physical punishment of children in February and even Zimbabwe banned the smacking of children in the home last month, he added.

Mr Baillie said: "Zimbabwe is an oppressive regime, seen by much of the Western world as a pariah state - but even children in Zimbabwe get better protection than they would in Scotland. The Scottish Government have an ambition for Scotland to be the best country in the world to bring up children. How can we claim that as long as we maintain this tradition of physical punishment?"

The argument against a smacking ban has been founded on parents' rights to decide how to discipline their children, claims that it does no harm and that a ban risks criminalising parents, but none of this is backed by evidence, Mr Baillie argues.

"Ireland changed the law and it has not resulted in parents being criminalised or being unable to control their children. There has been some evidence of a rise in people seeking help when they are in difficulties. There are other ways of being able to parent your child."

International evidence overwhelmingly supports a ban, he said. "The evidence couldn't be clearer. If you introduce equal protection[against assault] there is a corresponding reduction in the physical abuse of children."

If the law didn't exist, nobody would seriously contemplate introducing a law allowing the assault of children, he added. "People say a smack can protect a child from danger, but if you had an older person with dementia who was putting themselves in danger, because they don't know better, would the first thing you think of be to hit them, to get that across? Of course not. That just wouldn't be acceptable."

Mr Baillie said he accepted he might be characterised as an extremist for his stance but said change would come when this was no longer the case, viewing a change in the law as similar to the smoking ban - where a cultural change quickly became irreversible. "I think we will end up with parents saying 'why on earth did we tolerate this for so long.

"Many politicians privately agree with me but publicly they are reluctant to declare a position for fear of being accused of interfering in family life."

Mr Baillie is supported in his position by children's charities and many legal experts. Professor Sir Michael Marmot, Director of the Institute of Health Equity and the current President of the World Medical Association for 2015-16, contributed to a joint report Mr Baillie's office published with Barnardo's Scotland, Children 1st and the NSPCC in 2015 calling for change.

Sir Michael said: "The international evidence could not be clearer – physical punishment has the potential to damage children and carries the risk of escalation into physical abuse.

"Scotland is out of step with Europe and increasingly, the world. There is an urgent need for Scotland and the rest of the UK to comply with international human rights law and to prohibit all forms of physical punishment.”

Jackie Brock, Chief Executive of Children in Scotland, said: "We share Tam’s frustrations about lack of progress on this long-standing issue. Children are still the only group not to be protected by law from being hit.

Evidence is even stronger now of a link between poor emotional wellbeing over the long term and being hit as a child. Every parent should have the right to discipline their child, but there are certain circumstances and acts that can never be tolerated, and physical violence against a child is one of these. We will continue to press for a change in the law."

The Scottish Government's position is one of opposition to the physical punishment of children, but ministers have argued that changing the law risks seeing parents unnecessarily or unreasonably criminalised, and the best way of preventing smacking is by funding "positive parenting support".