Indeed. And this new policy will help the police/government to bring down criminality figures. I would be surprised if that is not the actual intent. In a few years they will triumphantly announce that the UK police is doing so well, that it has become a much safer place to live. Welcome to politics.
https://www.independent.co.uk/news/uk/crime/liam-allan-met-p...
where a rape trial collapsed after text messages between the alleged victim and alleged attacker were "discovered" late in the process.
So this is an instance of "we have to do something" where the suggestion swings too far the other way. I assume after some debate we will settle on a sensible compromise position.
Instead of forcing people to give their mobiles, why not use the "innocent until proven guilty" age-old adage?
They aren't forcing people to give up their mobiles, merely saying that if a victim chooses not to, they are denying the police useful evidence. In the absence of other evidence, there's a risk that prosecutions won't go ahead.
The reason this is an issue at all is the presumption of innocence. The accused is presumed innocent and without evidence (which may or may not be on the phone) there is nothing the police or the courts can do.