A Queensland Labor MP has hit back at legal criticism of anti-smacking laws to punish Queensland parents who used "excessive force" to discipline their children.

Member for Murrumba Dean Wells said vulnerable children would continue to suffer abuse if a loophole in Queensland's Criminal Code was not closed.

"The law currently operates as a defence for parents who commit serious assault, assault causing grievous bodily harm and even man-slaughter," Mr Wells said.

Mr Wells' call to outlaw smacking children was seconded by moves in the Labor Party to toughen its stance on smacking, made at its state conference in June.

However, Brisbane lawyer michael Bosscher, of criminal defence firm Ryan and Bosscher has said changes to the Criminal Code to make smacking illegal would be too difficult to prosecute.

"I am not advocating that good parents be subject to criminal proceedings," Mr Wells said.

"I am advocating that this loophole through which bad parents, abusive parents, can drive a horse and cart through be closed."

Under Section 280 of Queensland's Criminal Code it is lawful for a parent or a person in the place of a parent to use discipline management or control towards a child or pupil, if such force is reasonable under the circumstances.

"If your partner puts a brick through the windscreen of your car and in order to teach them a lesson you calmly take an implement and give them a good hiding, leaving bruises on their body, you will be charged ... and sentenced to a maximum of seven years' imprisonment," Mr Wells said.

"If on the other hand your child does exactly the same thing and you respond in exactly the same way, you will not be charged by virtue of the fact that s280 provides you with complete protection.

"Our law puts a higher value on the life of my partner than it places on the life of my daughter."

Mr Wells said parents who believed it was right to discipline their children with force would be pardoned under current law.

Two parents accused of tying their four children to a shed with a dog chain, beating them with shearing belts and stinging them with cattle prods, were acquitted of all charges under the Tasmanian equivalent of s280 in 1992.

"The Tasmania Law Reform Institute (commented) 'So long as the law permits physical punishment of children subject to the proviso of unreasonableness, the law will be obliged to give such genuine beliefs mitigatory weight'," Mr Wells said.

"Do we have the obligation in a democratic society to ensure that vulnerable children are protected? Certainly, yes."

However, Mr Bosscher has said practical difficulties would arise when police, lawyers and the courts tried to prosecute parents who smacked.

"Anti-smacking laws would be a controversial issue to prosecute in the courts because one police officers definition of excessively hard smacking could be radically different from another officers view," Mr Bosscher said.

Mr Wells said changes to the Criminal Code should be made to ensure s280 could not be used as a defence.

"This will not make criminals of good parents. This will put bad parents away," he said.