An amendment to the Children Bill banning parents from giving anything more severe than a "light smack" to their children has been widely condemned as unworkable.
Peers voted by 250 to 75 to reject a total ban on smacking, after both Labour and the Conservatives imposed a three-line whip forbidding them to support a total ban.
In a compromise amendment passed by 226 to 91 votes, parents could face up to five years in prison for causing physical harm such as grazes, bruises, swelling or scratches.
Labour MP and health committee chair David Hinchliffe said he would push for a complete ban when the bill returned to the Commons.
He warned that the amendment would just serve as license for lawyers to print money because of legal arguments over whether an assault had been committed.
Other commentators said parents would not know what degree of force they could legally use, and pointed out that physical evidence of bodily harm can quickly fade.
The campaign Children are Unbeatable, a coalition of children’s organisations, wants children to have the same protection from assault as that given to adults.
A spokesman for the campaign described the proposed change as irresponsible.
