LONDON (AP) — Police in England and Wales are distributing consent forms urging victims of sexual assault and other crimes to turn over access to mobile phones and other electronic devices or risk having their cases dropped.

The National Police Chiefs' Council said Monday that police will only seek access to mobile phone data when it is necessary for investigative purposes.

The opposition Labour Party's spokeswoman on justice matters, Shami Chakrabarti, says the consent forms are illegal.

"Any suggestion that rape victims must automatically hand over their phones in exchange for the support of the authorities is as unlawful as it is wrong," she said in a statement.

The forms have been introduced after several recent sexual assault cases collapsed when crucial evidence emerged from mobile devices.