Smacking is harmful to children's mental health and should be banned, school psychologists say.
The Association of Educational Psychologists has tabled a motion to the TUC Conference calling for physical punishment to be outlawed.
Presently, although corporal punishment is banned in schools, parents can "smack" or physically chastise a child as long as it is deemed "reasonable".
Psychologists say there are many better ways of teaching right from wrong.
Member of the AEP national executive committee, John Drewicz, will tell the conference in Manchester: "Smacking is harmful to a child's mental health, it models aggressive behaviour and it says to them that it is OK to use violence."
He will add: "Sixty countries already have full bans, including Sweden, Ireland, Spain, Germany and Portugal, and it is time to make violence against children illegal in the UK in all settings, including the home."
The motion also notes that the Welsh government is taking steps towards removing the defence of reasonable chastisement for parents.
But some campaigners have argued that parents would be criminalised if a smacking ban were to be passed.
There are also moves in the Scottish Parliament to ban physical chastisement of children.
A bill, lodged by Green MSP John Finnie, has been backed by the government and looks certain to pass at Holyrood.
Psychologists cite research suggesting that when force is used by parents, there are changes in their brain activity which mean the degree of force used on the child can escalate.
They argue that physical chastisement also leads to a lower quality of parent-child relationship, poorer mental health in childhood and adulthood, as well as higher levels of aggression in the child and more anti-social behaviour.
The biggest teaching union, the National Education Union, is seconding the motion.
Dr Mary Bousted, joint general secretary of the union, said parents and carers had a right to set boundaries for their children to help them develop social skills and good behaviour.
"However, we need to ensure that children are legally safeguarded in their own homes.
"We are not talking about dictating to parents how this is done but what we are saying is that it in 2018 beating children in anger, or as part of a pre-meditated punishment, is neither acceptable or defensible."
Sue Atkins, a parenting expert and former head teacher, said studies had shown that using physical force on children had caused anxiety and depression and damaged their self-esteem.
But Dr Stuart Waiton, a sociologist and campaigner at Be Reasonable Scotland, said parents did many things to children which if they were done to adults would be classed as unlawful.
He said: "What about grounding a child? If you grounded an adult it would be a criminal offence."