New laws are needed to ban parents from smacking their children, according to a Birmingham MP.
Lynne Jones (Lab Selly Oak) is one of 50 MPs calling for smacking a child to become a criminal offence. They have written to colleagues urging them to support a free vote in the Commons, in which MPs are able to vote how they wish without following instructions from party leaders.
Dr Jones has signed the letter along with colleagues including Wolverhampton MP Ken Purchase (Lab Wolverhampton North East).
They hope the Commons will approve the controversial proposals if Labour backbenchers are free to vote according to their conscience.
Although there have been calls to end smacking before, ministers have been reluctant to impose a ban. Critics have claimed that banning smacking would be the latest stage in the creation of a "nanny state" and could be a vote-loser for Labour.
But a free vote would allow the Government to put some distance between itself and any new laws.
The last time a smacking ban was debated on in the Commons, in 2004, 47 Labour MPs voted for reform. Ministers responded by promising a review, which reported back last October.
But the Government concluded there should be no change in the law.
Parents are currently allowed to smack their children so long as the violence does not amount to actual bodily harm. In practice this "reasonable chastisement" allows parents to hit children so long as they do not cause severe bruising. Teachers and carers are already banned from hitting children.
The letter signed by Dr Jones states: "We can see no logical reason whatsoever for putting Labour MPs in the intolerable position of choosing between party loyalty and the fundamental principle of equal protection for children.
"A free vote on this issue for Labour MPs is the sensible and fair way forward. It will satisfy our concerns and, at the same time, will allow Ministers to put a little distance between themselves and the issue.
"We appreciate the cautiousness of some colleagues. But we are absolutely convinced that the time is right and that this issue is no more a 'vote loser' than any of the challenging reforms that we have rightly embraced in the past three terms."
An Ipsos Mori survey of nearly 2,000 parents found more than half had smacked their children and 70 per cent thought it should remain legal.
The Government also has the support of the Conservative Party in rejecting a ban.