Home Secretary Theresa May hailed an "important step forward for child protection" as Sarah's Law, which allows parents to check if someone has a history of child sex offences, is to be rolled out nationally.
Mrs May said the programme, which followed the abduction and murder of eight-year-old Sarah Payne by convicted sex offender Roy Whiting 10 years ago, will also help police manage known sex offenders more effectively.
The Home Office scheme gives a parent or guardian the right to check with police if anyone with regular unsupervised access to their children has a criminal conviction for child sex offences.
Mrs May said: "The roll-out of this scheme is an important step forward for child protection in this country. Being able to make these checks reassures parents and the community and more importantly keeps children safer."
Sarah Payne's mother, Sara, was crowned the government's Victims' Champion after her ceaseless attempts to bring in the law based on the so-called Megan's Law in the US which allows the publication of names, addresses and pictures of paedophiles in some states.
More than 60 children were protected from abuse during the pilot scheme which started in four areas of the UK in September 2008, the Home Office said. Almost 600 inquiries to the four forces involved in the pilot led to 315 applications and 21 disclosures about registered child sex offenders.
The move was broadly welcomed by politicians and campaigners. Chief Constable Paul West, of the Association of Chief Police Officers, said: "These new arrangements are a major development in safeguarding children."
But some charities warned that the scheme could backfire by driving paedophiles underground. Diana Sutton, of the NSPCC, said: "We remain concerned about the risk of vigilante action and sex offenders going underground. All new local schemes need close management and proper resourcing to avoid this."
