Clare's Law - the Domestic Violence Disclosure Scheme - is designed to provide victims with information that may protect them from an abusive situation before it ends in tragedy. The scheme allows the police to disclose information about a partner's previous history of domestic violence or violent acts.
Today's national roll-out has been chosen by the Home Secretary to coincide with International Women's Day.
It follows a 14-month pilot in 4 police force areas, which provided more than 100 people with potentially life-saving information.
From today Domestic Violence Protection Orders (DVPOs) are also being rolled out across England and Wales. This new power will enable police and magistrates' courts to provide protection to victims in the immediate aftermath of a domestic violence incident.
A DVPO can last for up to 28 days, during which time the perpetrator can be prevented from having contact with the victim.
DVPOs are designed to give victims the time and space they need to make decisions about their options and future safety with the help of a support agency.
The implementation of Clare's Law and DVPOs are among the successful measures introduced to tackle violence against women and girls and form an integral part of the government's Call to End Violence against Women and Girls' Action Plan 2014.
The plan includes a commitment to put in place a new code of practice to ensure that safe addresses of victims of domestic and sexual abuse are protected. This will take effect where victims might otherwise have to reveal details of their address to people who could threaten them - for example in court cases unrelated to their abuse, or when required for their children's school records, or the family's access to benefits.
According to Theresa May, Home Secretary:
'Clare's Law and DVPOs are just 2 of a raft of measures we have introduced to hand control back to the victim by ensuring they can make informed decisions about their relationship and escape if necessary.'
'Clare's Law may help a few individuals but we need to help the majority of victims - not the few. The most effective way to save lives on a large scale is to improve police practice and protect the vital services run by specialist organisations like Refuge. Let's get our priorities right.'
More information on the scheme is available here.