MPs called on the government to impose a full ban on smacking yesterday, warning that loopholes in the law were allowing child abusers to escape justice.

David Hinchliffe, the chairman of the Commons health committee, said that present rules allowing "reasonable chastisement" of children left social workers "with one hand tied behind their backs".

According to a Mori survey for the NSPCC to be published next month, 83 per cent of MPs agree that "in some cases physical punishment can lead to physical abuse".