Known as Clare’s Law, the Domestic Violence Disclosure Scheme allows police to share someone's criminal history with their current partner if they feel they are at risk.
The Law’s ‘Right to Ask’ allows people to request disclosure from police about a potential abuser while ‘Right to Know’ sees officers seek permission to share information with someone about their partner.
Data from Her Majesty’s Inspectorate of Constabulary and Fire and Rescue Services shows Northumbria Police submitted 382 applications in the year to March 2020 under Right to Know and 273 were approved – 71%.
The figures show 662 Right to Ask applications were submitted and 397 disclosures approved – 60%.
Sarah Davidge, from Women's Aid, said a variation in disclosure rates among forces shows a "very worrying lack of consistency" that could impact on the safety of those at risk.
She added: “Right to Ask enables people to seek information if they are concerned their partner had been abusive in the past but, in 2020, only 37% of applications resulted in a disclosure.
"Many women who were worried about their partner's behaviour received, therefore, what may be perceived as confirmation that their partner's previous behaviour was not a cause for concern.”
A Home Office spokeswoman said: “As part of the landmark Domestic Abuse Bill we are putting the guidance on which the Domestic Violence Disclosure Scheme is based into statute.
"This will strengthen the visibility and consistent operation of the scheme.”