Paedophiles who pose as teenagers on the internet would face prosecution under proposed legislation making it an offence to go online to pick up minors for sex.
The new law, being prepared for this year's Queen's Speech, would cover e-mails, text messages and chatrooms, and would make it an imprisonable crime deliberately to use such new technology in order to stalk victims.
The police have been frustrated that known paedophiles have been using the internet to build relationships with children, often by posing as teenagers and pretending to have similar interests in common. At least a dozen men who made contact with their child victims on the internet have been imprisoned in the past year for sexual abuse and rape.
Police have been investigating whether Amanda Dowler, the missing 13-year-old from Surrey, was in contact with a man on the internet.
The new offence of "grooming", which is set to be incorporated in a wider Bill reviewing the sexual offences law, has been proposed by a task force set up by the Government to tackle internet paedophile crime.
The task force, led by the Home Office minister Hilary Benn, includes members of the Metropolitan Police's paedophile unit, child protection charities and opposition MPs. It was set up after the case of Patrick Green, who posed as a teenager to entice a 13-year-old girl from an internet chatroom to his home, where he sexually abused her. The 33-year-old, who worked for an export company in Slough, was jailed in October after admitting indecent assault and unlawful sexual intercourse with the girl.
Paul Burstow, the Liberal Democrat MP for Sutton and Cheam, whose victim was in his constituency, said the new law was welcome.
At a meeting this week the Home Office task force confirmed plans to introduce the "grooming" offence, which is likely to carry a five-year prison sentence. It will also give the police powers to arrest paedophiles who "groom" children for sex in other ways, such as taking them on trips and buying them sweets and hamburgers.
John Carr, internet adviser to the National Children's Society, who sits on the task force, said the move would help the police to arrest paedophiles before they had the chance to abuse children.
"This will give the police a new weapon to stop paedophiles getting hold of victims through the Net," he said. "Now they have to have proof that hands have been laid on a child.
"The point is that the internet has created whole new possibilities that were not there before for paedophiles."
* A woman has been charged with making nuisance phone calls to the family of Amanda Dowler, police said yesterday.
A Gloucestershire police spokeswoman said: "A 20-year-old woman from Tewkesbury in Gloucestershire has been charged with harassment of the Dowler family of Walton-on-Thames after their daughter, Milly, went missing on 21 March. She has also been charged with four offences under the Telecommunications Act."
The woman is due to appear at Cheltenham magistrates' court on 10 July.