Trials of a scheme that would allow Southampton parents to ask police if anyone with access to their child is a convicted paedophile begin today.

:: How will the pilots work? Parents in the test areas can ask the police if they are worried about someone involved in their child's life. For example, single mothers can ask about their new boyfriend if they are unfamiliar with their background. The test areas are Peterborough in Cambridgeshire, Stockton in Cleveland, Southampton and all of Warwickshire.

:: What do the police do next? The parent will prove their identity to the police and then fill in a form detailing their concerns. The police will carry out an immediate check on the individual taking no more than 24 hours. If the child is in danger, the police will act immediately, but not necessarily tell the parent. Then they will carry out a full risk assessment involving other child protection agencies and social services. The checks should take around 10 working days and no longer than six weeks.

:: When are parents told? The next step is for the police and ''Mappa'' (Multi Agency Public Protection) teams which supervise convicted sex offenders to discuss what they have found out and whether it will be passed on. If they find out the person is a convicted paedophile, there is a ''presumption'' that information that is ''relevant, necessary and proportionate'' will be given to parents. Parents may also be told if police have intelligence about the person or details of convictions which are non-sexual but may also put the child at risk, such as a history of domestic abuse.

:: Can parents tell their neighbours or other parents? No. What the police tell parents must be kept confidential. If police fear parents will tell others they can decide not to reveal it. There are civil punishments for passing on the information, and criminal penalties if it is used to provoke an attack on the paedophile, for example.

:: How does this differ from the American scheme? In America much more information is available, and without you having to ask for it. Many states use the provisions of ''Megan's Law'' introduced more than 10 years ago after a convicted paedophile killed a young girl after moving in across the road. Names, address details, photographs and details of convictions are routinely published on websites.

:: Why don't we have that here? There were fears such a law would prompt paedophiles to evade the authorities, making them more difficult for to monitor. It might also breach human rights laws.