Backbench MPs are calling for a free vote outlawing smacking. Labour backbench MPs are leading an attempt to ban the smacking of children.
Around 50 backbencher MPs are calling on a free vote on the issue. They plan to table an amendment to the children and young persons bill, due to go to the Commons from the Lords next month.
Greg Pope, a former Labour whip and one of the campaign leaders, said:
"It is simply wrong that a form of violence that would lead to criminal charges if it was inflicted on an adult is lawful so long as a child is the victim."
In 2004, 47 Labour MPs failed to outlaw smacking when they rebeled against the party whip to vote for an all-out ban.
The 2004 Children Act removed the legal defence of "reasonable punishment" for parents and carers who assault their children. Under the Act, parents are currently allowed to smack their children as long as it doesn't leave visible bruising, grazes, scratches, minor swellings or cuts.