A pre-trial review hearing in the case of Mr John Gilligan will be held at the Old Bailey in London this morning, as doubts remain over the start of his trial on Monday next.Mr Gilligan, who is charged with four drug-trafficking offences, is not expected to appear in court. He will remain at the high-security Belmarsh Prison in south-east London where he has been held since his arrest at Heathrow Airport in October.Counsel for the prosecution travelled to Dublin last week, but they have refused to discuss the details of the visit. However, it is understood that despite discussions between the two sides in the case, difficulties involving the presentation of witnesses and evidence have not been resolved.Mr Gilligan was arrested on October 6th last year as he attempted to board a flight to Amsterdam.