The High Court said a new inquest should be held into the death of Michael Carr, 41, the former MP for Bootle, after deciding an original inquest jury had been unlawfully summoned.
The court was told that the original inquest, opened by the Liverpool coroner, Stanley Barter, was adjourned for further inquiries.
It resumed without a jury in February 1991, but the coroner agreed to summon one after family lawyers said he was obliged to do so. As a 'short cut', nine jurors were obtained from Liverpool Crown Court.
The inquest was adjourned after four days for the Director of Public Prosecutions to consider bringing manslaughter charges after the jury was told a nurse at Walton Hospital did not pass on details of Mr Carr's symptoms to a doctor.
When the DPP ruled, 13 months later, that there was insufficient evidence for criminal proceedings the inquest resumed without one member of the jury. It was adjourned again so that the MP's wife could challenge the legality of the proceedings.