A spokesman for the National Society for the Prevention of Cruelty to Children (NSPCC) said its helpline had been inundated on Tuesday night after the start of its Full Stop television advertising campaign.

The adverts, which are so hard hitting they cannot be shown before 9pm, feature the Spice Girls and England football captain Alan Shearer.

The stars, who are icons for many young people, are seen with their hands over their eyes, in a repeated symbol signifying that child abuse is too horrifying to watch.

The NSPCC says the Full Stop Campaign is one of its most ambitious challenges since it was founded more than 100 years ago, and is the start of a programme that will run for two decades.

BBC Social Affairs Correspondent Alison Holt: This NSPCC campaign is considered unrealistic by some

The powerful new television adverts and posters depict shots of a home scene, with the "voice" of an abuser in the background.

Children's toys such as a teddy bear and Rupert Bear also feature in the hands-over-the-eyes pose.

Lady Thatcher's wish

The NSPCC highlights shocking statistics such as: Every week at least one child is killed through abuse or neglect and those most at risk of being killed are less than 12 months old.

One advert shows a poster of Alan Shearer in a child's bedroom

Some 35,000 children are on child protection registers, considered to be suffering or likely to suffer significant harm.

The Spice Girls said in a statement that the campaign should reach out to everyone in Britain. "We hope it will make people sit up and listen to the needs of children who are neglected and abused, and we are proud to be involved from the start."

The initiative also has the backing of other charities, such as Barnardo's, ChildLine and Save the Children, as well as politicians including Deputy Prime Minister John Prescott and Baroness Thatcher.

Lady Thatcher said: "If I could be granted just one wish for the next millennium it would be that cruelty to children should be no more. What joy such good news would bring to us all."

The NSPCC says it is aiming to make everyone in society responsible for helping to protect children.

It will offer children help and advice through the media and the Internet.

And the charity plans to expand its services to reach more children, including setting up a network of electronically-linked advice and support centres, and up to 16 regional investigation units.

Target 'unrealistic'

But some experts say that however laudable, completely eradicating child abuse is unrealistic.

See no evil: An Action Man covering his eyes features in one advert

Diana Hinings, a lecturer in social work at the University of East Anglia, said: "It's a very noble aim, but unlikely to ever be achieved, because there's always an in-built inclination for larger, more powerful people to take out their frustrations on smaller, weaker people like children.

"Also, child abuse gets redefined, the most recent definition being corporal punishment. Even the way we discipline children, inducing guilt, can be defined as emotional abuse."

But the NSPCC is basing its campaign on a report three years ago which found that most child cruelty can be prevented, provided the will exists to do so.

Most instances of abuse arise in the home.

And charity chiefs say they want to bring about fundamental changes in attitudes towards children.

Helpline cases

Senior helpline counsellor John Cameron said: "It's realistic for the NSPCC to have a vision.

"You can only end child abuse when everybody is committed. That might be pie-in-the-sky to some extent but we would be neglectful if we didn't seek to end it."

A caller to the charity's helpline recently told of a thin-looking 10-year-old regularly seen by a neighbour foraging through dustbins looking for food.

Another called to report how three children were regularly left in the care of a known paedophile while their mother went out drinking.

Mr Cameron told BBC News Online about a mother, in her 30s, who contacted the NSPCC to seek help in coping with her anger when her abusive father died.

"She had become overly protective of her own children and she risked inadvertently exposing them to risks because they could have grown up also fearing people.

"Children must have the freedom to go out and be children," he said. The mother was helped to express what she would have said to her father and consider the options for how to behave towards her own children.

Call for commissioner

About 80,000 callers ring the charity's helpline each year. Under the new plans, it will expand to offer Welsh and Asian language counsellors.

NSPCC chief executive Jim Harding: This should be the social cause of the millennium

Other campaign targets include providing Protective Curriculum materials giving schoolchildren advice on keeping safe, bringing training to teachers and calling for a national Commissioner for Children.

NSPCC chief executive Jim Harding said: "There is no doubt this should become the social cause of the millennium.

"A campaign of this magnitude offers the prospect of a different sort of society for us all, not just for those children whom we help and protect."

The hands-over-the-eyes theme is based on research for the NSPCC suggesting most people choose to ignore child cruelty. Mr Harding says: "The advertising sums up the prevailing climate. It reflects a culture in denial about what is happening."