Rape is already under-investigated and under-prosecuted in the UK, and we've seen numbers of prosecutions declining alarmingly after the cases that caused this new guidance to be issued.

So we don't need to wonder, we know: police and CPS administratively close the case.

Can you share the data that show the numbers of prosecutions declining per reported case, before and after the new guidance was issued?

As a comparison, I am reminded of Swedish statistics. Both people being assaulted in the home and sexually assaulted shared the same clearing rate. If rape is under-investigated in the UK we should expect those data to look very different unless both crimes are under-investigated, in which case I must ask what the norm is for which the claim of under-investigated is based on.

The claim for under-investigation comes from the fact that in English law rape is a very serious offence, and carries a similar sentence structure as murder. There are 150,000 rapes per year (according to the annual crime survey, which probably under-counts rape) and there are only 5,000 prosecutions each year.

Here are the stats showing decline after the collapse of the high profile cases: https://www.ons.gov.uk/peoplepopulationandcommunity/crimeand...

Here are some news reports:

https://www.theguardian.com/society/2019/mar/06/prosecution-...

https://www.bbc.co.uk/news/uk-48095118

https://www.independent.co.uk/news/uk/crime/crime-statistics...

https://www.bbc.co.uk/news/uk-45650463

So they're just assuming that the victims data will be their best lead?

How about everyone just keeps a secondary dumb phone to hand over when they feel that the police request is unreasonable.

TFA basically says that they won't work on the case unless the victim complies.

Yes it also quotes the phrase “Police have a duty to pursue all reasonable lines of enquiry,”.

Who's judging what's reasonable here? What stops them making requests victims would rightfully consider unreasonable so the police can just claim that the victim was uncooperative so it doesn't negatively impact police statistics?

I guess that they're raised the bar on "cooperative". So if you've been the victim of a crime, you can't report it if there's any evidence of totally unrelated crimes. Say that you were raped, but had also ordered illegal drugs from your phone.

Obstruction of justice?

If the victim has reason to belive their data would lead to a conviction the police wouldn't need to ask for it

This was spurred by the opposite - cases where the accuser's data led to complete exoneration and public apology.