In the UK and across the world, rape is notoriously difficult to prosecute. The nature of the crime means that it often comes down to one person’s word against another. Added to this are complex societal biases around morality and gender roles, and the associated practical issues of victim-blaming and inadequate investigation. The under-reporting of sexual assault – which goes hand in hand with anxiety about not being believed – is another major problem.

So it is a cause for concern – if not entirely surprising – that although reported rapes have gone up by 3 per cent in the last two years, the number of cases referred to the Crown Prosecution Service (CPS) for charging decisions has fallen by a third. The actual number charged with rape has fallen by 14 per cent in the same period. In an investigation for the Independent, the Bureau of Investigative Journalism (BIJ) has suggested that this fall in referrals may be connected to changes in CPS guidance. The changes, introduced in 2011, place more emphasis on police forces identifying and stopping cases before they get to the CPS if the standard for charges isn’t reached. This was intended to save time and money; but critics say that in practice, the police may be dismissing cases that could be successfully prosecuted.

The latest figures continue a trend that has been evident for several years. In October 2013, the shadow attorney general Emily Thornberry expressed concern about cases never reaching the CPS. Figures outlined then (in an answer to a parliamentary question) showed that rape allegations handed to prosecutors had hit a five year low, despite a 30 per cent increase in the number of rapes reported to police. “The CPS is doing a lot of work on trying to improve the way in which they prosecute these cases and that is to be applauded, but if they are not being given the cases to prosecute you have to ask why that is,” said Thornberry at the time. “I don't know the answer to that. I do, though, know the police have been subjected to 20 per cent cuts and they are difficult cases to prosecute, with vulnerable prosecution, witnesses that take a lot of time. I'm seriously concerned that there may be corners being cut."

In recent years, there has been a lot of debate about rape conviction rates and the way they are reported. Back in 2010, Baroness Stern, the author of an independent government-commissioned report on rape investigations, said that it was unhelpful to focus on the fact that just 6 per cent of reported cases resulted in a full conviction for rape. Stern argued that this was putting women off from coming forward, and pointed out that 58 per cent of the cases that did go to court resulted in convictions – very similar to rates for other crimes. Vera Baird, then solicitor general, disputed this, saying that although the 58 per cent rate was important (and a major improvement), the 6 per cent figure should not be downplayed “as it reflects the high number of rape victims who drop out before they get to court.”

It is those victims, who never even get to court, whose plight is highlighted by today’s figures. If more victims of sexual assault are coming forward, that is a good thing. But those leaps and bounds forward are made irrelevant if their cases are not investigated fully. Second-guessing the future in this way, by shelving cases that could have a chance of conviction, is not justice.