BKR, R. v [2023] EWCA Crim 903, July 28, 2023, at paragraphs 34, 52 and 70:

The power of a criminal court to stay a prosecution as an abuse of the process of the court is an important one, but it is not unlimited. Its existence and scope was the subject of disagreement between the judges in Humphrys, but that was settled in Ex p. Bennett subsequently. It has since been developed and refined by the Privy Council and the Supreme Court. Ex p. Bennett explains that there are two species of abuse of process (or “limbs”) which justify a court ordering a stay of criminal proceedings. The first is that a fair trial is not possible. There is little that needs to be said about that. If the court concludes that the trial under consideration will not be fair, then it will prevent it from happening. The second limb therefore does not arise unless the defendant, charged with a criminal offence, will receive a fair trial. It seems clear that something out of the ordinary must have occurred before a criminal court may refuse to try a defendant charged with a criminal offence when that trial will be fair.

The powers of the court to stay a prosecution as an abuse of process are a very important part of the jurisdiction of the criminal courts, but they are limited and a stay is an exceptional remedy. The courts must exercise care and restraint in their use, particularly where the issue is a decision to prosecute a case to trial. That decision is entrusted by Parliament to the CPS and it is, in the ordinary case, no part of the function of a judge to say who should be prosecuted and who should not be.

We will direct that the proceedings should take place at a court in London other than Woolwich because members of the judiciary there have expressed their views so clearly (as they were entitled to do) that the complainant in this case may be concerned that her allegation will not be tried in a way which is fair to her. We are quite confident that this concern would be misplaced and that she would be treated properly by the judges at that very strong Crown Court centre, but in order that this case should now have a fresh start, we will direct that the Presiding Judge for London should allocate this trial to a court other than Woolwich.