SA row over smacking children

South Australian Democrat MP Sandra Kanck has criticised a move in State Parliament to legally endorse the smacking of children.

Family First Upper House member Dennis Hood has introduced a bill seeking to endorse the legality of "reasonable chastisement" of children.

Ms Kanck says research shows that smacking does not improve children's behaviour, and teaches them that violence is a way of resolving conflict.

Ms Kanck says the bill does not clarify what constitutes a reasonable level of smacking.

"This is such a grey area and the definition in the bill does nothing to assuage my fears about [it] and how it could be used to justify the unjustifiable." she said.

Ms Kanck says the proposal could contravene the United Nation's Convention on the Rights of the Child.

She says the convention calls on governments to protect children from all forms of physical or mental violence and abuse, including while in the care of their parents.

"So if you read the UN Convention on the Rights of the Child, this would actually be saying that we ought not pass legislation such as this." she said.