General principles – role of the prosecutor or the prosecuting advocate
The private prosecutor must be reminded that all lawyers instructed by the prosecution in a criminal trial must comply with their professional duties, as defined by the relevant professional bodies.
Where no such professional obligations apply, the private prosecutor should endeavour to adhere to this Code and conduct the prosecution by the same high standards.15
The private prosecutor should also be made aware that any advocate it instructs will comply with the guidelines on the role of prosecuting advocates first formulated by Lord Justice Farquharson in 1985:
‘It is well known to every practitioner that counsel for the prosecution must conduct his case moderately, albeit firmly. He must not strive unfairly to obtain a conviction; he must not press his case beyond the limits which the evidence permits; he must not invite the jury to convict on evidence which in his own judgment no longer sustains the charge laid in the indictment.’
As Lord Thomas observed in R v Zinga (op cit):
‘Advocates…who have conduct of private prosecutions must observe the highest standards of integrity, of regard for the public interest and duty to act as a minister of justice (as described by Farquharson LJ) in preference to the interests of the client who has instructed them to bring the prosecution.’
Disclosure mid-trial and the taking of instructions
There is a continuing duty on the prosecution to keep disclosure under review. The private prosecutor should be advised in advance of the trial that disclosure could be made without reference to them, either generally in the proceedings or in certain exceptional circumstances, for example, if they are giving evidence.
It may be that the private prosecutor’s evidence discloses the existence of material which has not been provided to their lawyers for review. In those circumstances, disclosure should be made to the Court and defence of the fact that no such material has been made available for review. Exceptionally, it may be appropriate to seek permission from the trial judge and defence to speak to the private prosecutor for the sole purpose of locating any such material.
15R v Zinga  1 Cr. App. R. 27, R v George Maxwell (Developments) Ltd (1980) 71 Cr App R 83.