Judges at the European Court of Human Rights in Strasbourg ruled that British law, under which the stepfather was initially acquitted, failed to protect the basic rights of the boy, who was nine at the time of the caning.
"Child A", who cannot be named for legal reasons, was awarded pounds 10,000 in damages plus pounds 20,000 in legal costs. But the ruling also means that ministers will have to amend the law to take account of the judgment. A consultation paper is expected by Christmas and one likely option is that hitting children with a stick or other object will be made illegal.
The case of Child A arose in 1993 when the boy was examined by a paediatrician who found a number of bruises apparently caused by beatings with a garden cane.
The child's stepfather was charged with causing him actual bodily harm and at the subsequent trial, in 1994, did not dispute caning the boy but argued that this amounted to "reasonable" punishment. The jury acquitted the stepfather on a majority verdict, but Child A, backed by his natural father, tested the law against the European Convention on Human Rights, of which the UK is a signatory.
In Strasbourg yesterday judges ruled that the treatment of Child A, who is now 14, was severe enough to reach the level prohibited by Article 3 of the Convention which states that "no one shall be subjected to torture or to inhuman or degrading treatment or punishment".
The court ruled that English law, under which the prosecution must prove that an assault on a child is beyond the limits of reasonable punishment, did not provided sufficient protection.
The ruling, hailed by the boy's lawyers as "one of the biggest changes in child protection law for 130 years" immediately provoked a political row, with the Conservative Party leader, William Hague, claiming that it takes "the nanny state too far".
Meanwhile, pressure groups stepped up calls for a ban on smacking which would bring the UK into line with eight other European countries. Anything less would produce confusion and result in contradictions, they argued.
While promising to change the law, the Government moved swiftly to distance itself from calls for an all-out ban on smacking in the home. Paul Boateng, the Health minister, said: "Any case of serious violence against a child, and especially in this instance, [where] a young boy was being repeatedly and severely beaten at home, would horrify parents. There is no excuse for such behaviour and it is right and proper to condemn it.
"But this is nothing to do with the issue of smacking. The overwhelming majority of parents know the difference between smacking and beating."
But Mr Hague argued: "We have taken the nanny state too far when we have to have court rulings about what people can do with their own children in their own home on things like this.
"It's up to parents whether they want to smack their children. They don't need a European judge to tell them whether or not they're allowed to do that," he said
Michael Gardner, litigation partner for Morgan Bruce, the legal firm that represented the boy, said: "I am delighted for Child A who fought this case not only on behalf of himself but to help other children.
"This is one of the biggest changes in child protection law for 130 years. We await the government legislation with interest - it is likely they will consider banning implements altogether."
Janet Convery, co-ordinator of the forum on children and violence at the National Children's Bureau, said: "We welcome the judgment and hope that the Government will take the opportunity to ban physical punishment and give children the same legal protection that adults have."Reuse content