CAMPAIGNERS have renewed calls for a ban on smacking after a major new study carried out in Scotland found significant evidence it posed a serious risk to children's development.

It found youngsters who had received corporal punishment before the age of two were twice as likely to have emotional and behavioural problems when they start school as those who had not.

Alison Todd, director of children and family services at the charity Children 1st, said Scotland, as part of the UK, was now one of only four European Union countries not to have banned physical punishment of children.

"As this research indicates, hitting a child as a way of disciplining can clearly have damaging impacts on their development," she said. "It is a situation 'deeply regretted' by the UN Committee on the Rights of the Child and the Children are Unbeatable coalition of which we are a member."

She added: "The Scottish Government has a number of current legislative opportunities through which to address this issue. We share the Government's aspiration for Scotland to be the best place to grow up, and giving children the same right to protection from assault that adults enjoy would be a huge step towards making it reality."

Under the Criminal Justice (Scotland) Act parents are allowed to hit a child so long as the punishment goes no further than "reasonable chastisement". They cannot hit a child on the head or with an implement, or shake a child.

The new study is the first piece of research to explore the association between parental use of smacking and emotional and behavioural problems in young children living in Scotland.

Dr Sonya Scott, a public health specialist at NHS Greater Glasgow and Clyde, was the lead researcher on the project carried out at the Institute of Health and Wellbeing at Glasgow University.

She also called for new laws to be introduced to ban smacking. The researchers analysed the behaviour of 1600 Scottish children around the age of 46 months, including 327 who had received corporal punishment before they were 22 months old.

Adjustments were made to take account of the family's socio-economic background, the child's gender and number of siblings.

The study found more than 13% of those who had been smacked scored poorly on a standarised questionnaire used by doctors and health visitors to assess a child's social development.

Of the children who had not been smacked, just 6% had "abnormal results".

The assessment, called the Strengths and Difficulties Questionnaire (SDQ), covered ability to get on with peers, hyperactivity, and conduct.

"The association between exposure to main care-giving smacking and behavioural problems was also evident when emotional and behavioural problems were measured by parent-reported SDQ scores, with 13.4% of smacked children having abnormal scores compared with 5.9%of children who had never been smacked," said the study published in the academic journal Child: Health, Care and Development.

A decade ago Scottish ministers dropped a ban on corporal punishment of children under three after a public backlash. Police warned a ban could give them increasing workloads and be unworkable.

A Scottish Government spokesman said it did not support smacking. However, it did not wish to criminalise parents for lightly smacking their child. He added: "The Criminal Justice (Scotland) Act 2003 clearly outlines what is unacceptable punishment."