The BBC's Jon Brain: Supporters in court shouted "shame on British justice"

Horne, 46, from Northampton, who was accused of causing millions of pounds worth of damage to shops in arson attacks, was sentenced in December 1997 to what is believed to be the longest prison term for an animal rights activist.

The former dustman, who came close to death while staging a hunger strike last year in a protest against vivisection, was found guilty by a jury at Bristol Crown Court on charges of arson and attempted arson.

Horne, described as "a one-man organisation called the Animal Rights Militia" - argued that the conviction was unsafe because of the judge's summing up before he was sentenced at Bristol Crown Court.

Horne is serving his sentence in Full Sutton prison in York

Mr Alaistair Edie, for Horne, from Northampton, said the judge had caused "unknown and unknowable" prejudice to his client by refering in his summing up to the jury "other suspects" and whether there were likely to be any.

Such a possibility had not been canvassed during the evidence, which was not in any event "overwhelming" against his client.

Mr Horne went on hunger strike in an attempt to force the government to set up a Royal Commission into vivisection.