Political statements can be repeated effectively outside court, through public speaking or media conferences on the steps of the courthouse, for instance. This needs to be well-organised in order to get maximum media attention. But you also need to consider the impact upon the court case itself.
It is well worth consulting with your legal representatives. Magistrates have no real power of contempt outside their own court rooms and contempt actions have generally only been laid after public comments very close to a jury trial.
Public comments about the political issues surrounding a protest action, or about police behaviour at that action, can still be made. The fear of getting charged with contempt can deter important public comment.
Contempt of court
The laws of contempt are designed to protect the principle of the right to a fair trial. In general the law of contempt prevents the publication of material that is prejudicial about matters that will be or are currently before the courts. In popular parlance the purpose of contempt law is to minimise the likelihood of 'trial by media'. Types of information which are considered prejudicial include: details of prior convictions; the creation of an adverse impression of the accused; statements about guilt or innocence of the accused; and in cases where identification of the accused is in issue, the naming of the accused or the provision of other means by which the accused may be identified.
There is a limited form of defence of 'public concern'. However, the closer the comment is directed to the actual subject matter of the trial the less likely it is that this defence will be available. The defence is intended more to protect the publication of material in the context of ongoing public debate about the broader issues, where the risk of prejudice to a trial is incidental and unintended, rather than discussion of the specifics of any particular trial.
Contempt law is against any public comment on an issue that is before the courts and is to be decided by the courts. Notice, though, that the issue to be decided is often a narrow one (did a person commit a particular offence), and does not prevent public discussion of the background or wider context of the events concerned.
So for instance, the charging of a demonstrator at an environmental action does not prevent others from criticising police operations at that demonstration, or from talking about what the action was all about. However, some lawyers advise against public comment that in any way relates to a court case.
People are not prosecuted for proclaiming their innocence of a charge, which is their right.