When deciding whether or not to prosecute in cases of rape, the Crown Prosecution Service applies the full code test set out in the Code for Crown Prosecutors. This consists of two stages. First, there must be sufficient evidence to provide a realistic prospect of conviction. Secondly, a prosecution must be in the public interest.
There is no difference in the way that decisions to prosecute are made in rape cases as compared with any other case. The full code test must be met before any prosecution can be brought, regardless of the type of offence.