Parents who smack their children are more likely to go on to abuse them, and youngsters who suffer the punishment can suffer lifelong effects, according to a major new report.

The research commissioned by leading charities and the Children's Commissioner found smacking can lead to depression and there is a greater chance that the children will go on to be violent themselves.

Its authors argue that not only is the common view that 'it never did me any harm' likely to be wrong, the evidence that physical punishment is harmful is now so overwhelming that it should be prohibited by law.

The report criticises the Scottish Government for continuing to maintain that a low level of physical punishment is acceptable.

Instead it should be viewed as a clear violation of children's human rights, the authors say, and children should be given more, not less protection from violence than adults.

The study, commissioned by NSPCC, Barnardo's Scotland Children 1st and Scotland's Children's Commissioner, says that a change in the law should be accompanied by an awareness campaign and the offer of support and lessons to parents.

A legal change should not be about prosecuting parents, the authors say, but add: "The perception that legal reform risks criminalising parents must be weighted against the real, evidence-based risk to children of retaining a defence in the law, allowing their justifiable assault."

The evidence in the report is drawn from a review of 74 studies carried out around the world over the last 10 years, including the findings of two pieces of research in Scotland, the Millennium Cohort Study (MCS) and the Growing Up in Scotland (GUS) reports.

Of 55 original studies on bad behaviour such as aggression and misconduct, 42 found that physical punishment made it more likely a child would misbehave, even after allowing for the fact that 'naughty' children might be smacked more.

One study which included 1600 Scottish toddlers, showed that children who had been subjected to smacking during their first two years were more than twice as likely to display emotional and behavioural problems at age four than children who had not been smacked.

"There is strong and consistent evidence from good quality research that physical punishment is associated with increased childhood aggression and antisocial behaviour." the authors of the new study conclude.

"In other words, parents who are using physical punishment in response to perceived problem behaviour are likely to make it worse."

They add that the reviewed studies also show a consistent link between physical punishment and child maltreatment. "Physical punishment carries a worrying and serious risk of escalation into injurious abuse and maltreatment," they add.

Although more than half of children and parents report that smacking and other physical punishment are a feature in the family home, most accept that it doesn't work, the study says. While the MCS research found that 58 per cent of Scottish mothers reported smacking their five year old children, the GUS study found that 80-90 per cent of Scottish parents admit that smacking is not very or not at all useful.

One of the authors, Dr Anja Heilmann, said: "Our review dispels the myth that physical punishment is a necessary disciplinary tool. Evidence shows that the vast majority of parents express highly ambivalent and negative feelings about its use. Where the law has been changed, this has not led to the criminalisation of parents. rather , the law is of strong value, which combined with positive parenting campaigns results in a faster reduction in the use of physical punishment."

Co-author Sir Michael Marmot, professor of public health at the University of London added: "As well as ringing alarm bells, this review should also spur us into action. Scots law is out of step with the Scottish Government's highly laudable approach to child wellbeing which focuses on prevention and early intervention."

The call for a legal change is being backed by a range of organisations including the Royal College of Paediatrics and Child Health, the Scottish Police Federation (SPF), Scotland's Children's Commissioner Tam Baillie and the Royal College of Nursing (RCN).

Brian Docherty, chairman of the Scottish Police Federation said: "We recognise that many assaults on children occur within a domestic environment and we support efforts to reduce such asaults and to make Scotland's children safer."

Theresa Fyffe, director of the RCN said: "A modern Scotland requires a totally unambiguous message about what is and is not acceptable in how we treat our children."