Jailed Liverpool fan Michael Shields has won an important battle at the High Court in London in his bid for a free pardon. Shields, now 22, is serving a ten year sentence for the attempted murder of a barman at the Big Ben diner in Varna, Bulgaria, in 2005. MPs, clergymen, Liverpool FC players and many others have backed the call to free him on the basis that he is innocent. Two senior judges have ruled that Justice Secretary Jack Straw has the "power and jurisdiction" to exercise the ancient "royal prerogative of mercy" in the case of Shields, who was convicted abroad but transferred to a UK prison to finish his sentence. But the judges also ruled that it was for Mr Straw alone - and not the courts - to decide how to exercise that power. The ruling means Shields does not have an automatic right to his freedom. Mr Straw's legal team argued at a recent High Court hearing in London that there was no jurisdiction to grant Shields a free pardon. They warned that, if the Justice Secretary did intervene, the move could be seen as criticism of the foreign court that found Shields guilty. But Justice May and Mr Justice Maddison, sitting in London, said: "We declare that he does have such power and jurisdiction." The judges stressed that it was not for the court to say "whether or how that power may be exercised". The Liverpool fan has always vehemently maintained his innocence, and Fair Trials Abroad described his conviction - based solely on identification evidence with no supporting testimony - as a blatant miscarriage of justice. Another fan, Graham Sankey, had signed a confession - later retracted - that he was the man responsible, but the Bulgarian Supreme Judicial Council said the new evidence did not prove anything and merely introduced doubt. Pete Weatherby, appearing for Shields, told the judges his conviction was based on thin evidence. Mr Weatherby said there was also fresh evidence to support the call for a free pardon.