I ask again - what trial? Who or what is going to be on trial? Trials are for criminal matters - are the CPS in volved, or are you talking about a private criminal prosecution, or are you talking about a civil action?
If criminal, what criminal charges are you wanting to bring and against whom?
If you are talking about a civil action, who is it supposed to be against and what outcome are you wanting to achieve? Is this really only about trying to get compensation?