There must be some remedy open to someone who is bailed seemingly interminably, say for a year or more, but I can't think what it is. Perhaps there isn't one. Perhaps a judicial review by the High Court ? Arrest is on reasonable suspicion that a crime has been committed and the arrested person committed it . If, after a long time, the CPS haven't got enough evidence to charge someone on a simple complaint in a straightforward case, the presumption ought to be that the original suspicion has not been confirmed or justified