Jailed Liverpool fan Michael Shields won an important High Court battle today in his bid for a free pardon.
Two senior judges ruled that Justice Secretary Jack Straw did have 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.
Shields, now 22, is serving 10 years 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.
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 judges ruled the Justice Secretary did have power under Article 12 of the Convention on the Transfer of Sentenced Persons 1983 "to consider at least granting pardon to Michael Shields on the facts presented to this court".
The judges said the Bulgarian judicial process had been concluded, but they were told there was fresh evidence which had not been considered by the the Bulgarian courts.
"It is, in our judgment, open to the Secretary of State to entertain a request to exercise the royal pregorative. It is not for this court to say whether or how it might be exercised."
The barman was attacked a few nights after Liverpool's European Cup Final victory in Istanbul, Turkey.
Shields was initially jailed for 15 years in Bulgaria, but was transferred to the UK in 2006.
He is serving the remainder of his sentence, which was cut to 10 years on appeal in Bulgaria, at HMP Haverigg in Cumbria.
He 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, 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.
In a statement, Justice Secretary Jack Straw said: "I have carefully considered the judgment of the High Court and will not be appealing it.
"As the judgment makes clear, the issue the court was considering was a purely legal one - whether I had been correct in taking the view that I had no power to consider a pardon in this case, on the basis that only the Bulgarian authorities could reconsider the case.
"The court was not asked whether or not Michael Shields was innocent or guilty and it does not come to a view on that, nor does it order a grant of a pardon. Rather, the court concluded that it is 'open to the Secretary of State to entertain a request to exercise the royal prerogative'.
"In light of the criteria which the court then set out, I am today establishing a process under which I will examine the case to the extent that the court has indicated that I am able to do so. I intend to appoint senior counsel to advise me on the next steps.
"I will ensure this process is undertaken as quickly as possible, and can assure Michael Shields and his family that I will reach a decision on whether to recommend granting a pardon as swiftly as is possible. While recognising the frustration of Michael Shields' family and his campaign team, I am also duty bound to work within the law.
"I am also considering the wider consequences of this judgment on other cases, including its implications for British prisoners abroad."
Liverpool Riverside MP Louise Ellman, who has been campaigning on behalf of Shields, said the judgment was a "major breakthrough".
"The grave miscarriage of justice carried out in Bulgaria can now be set right in the UK," she said.
"I ask Jack Straw to look at this case with great urgency."
The High Court said the grant of a free pardon appeared to require a conclusion that Shields was "morally and technically innocent".
That involved "taking the Bulgarian courts' judgment for what it is, and without calling in question its correctness on the material those courts considered".
It also involved considering "fresh evidence which the Bulgarian courts did not consider, taken with the material which they did consider and their judgment upon it".
But the judges stressed the fresh evidence "does not apparently include Graham Sankey's confession because that has been considered by the Bulgarian appeal courts".
During the recent hearing that led to today's landmark ruling, Mr Straw's legal team warned that judgment in favour of Shields could "drive a very big hole" through the international convention on the transfer of prisoners that allows convicts to serve their sentences in their home countries.
Pete Weatherby, appearing for Shields, told the High Court his conviction was based on thin evidence and he met the criteria for being declared morally and technically innocent.
Applying for judicial review, Mr Weatherby said there was strong circumstantial evidence supporting Sankey's confession.
Fresh evidence included the fact that two men - friends of Sankey's who were properly convicted for their part in the violence in Varna - had "admitted to a senior public figure that Mr Sankey was the third man, and not Mr Shields".
Sankey had also pleaded guilty and been imprisoned for another offence of late-night violence on a barman in Liverpool "which happily did not have such dire consequences".
The judges heard that Shields passed a polygraph lie-detector test.
They were told Mr Straw had taken a close interest in the case and met the Bulgarian minister of justice, Miglena Tacheva, to discuss the matter.
Recently Shields's mother Marie met the Prime Minister's wife Sarah Brown at 10 Downing Street over her son's case.
The Bishop of Liverpool, the Right Rev James Jones, described the case as "a travesty of justice".
Shields also has the backing of the team he supports. Liverpool players have worn "Free Michael now" T-shirts while warming up for games.
Celebrating today's news, the prisoner's father Michael senior said his son was "not in the best of health" but their dream "has nearly come true" with him possibly being freed.
He said: "Michael was a bit emotional when he found out.
"It has taken its toll on Michael, he is not in the best of health or the best of spirits.
"He was only 18 when he went to Bulgaria, he's 22 now.
"I'm sure he is very happy with this decision and basically we just need to get him home as soon as possible now."
Shield's mother Marie said: "I am very hopeful he will be home for Christmas.
"All I want to see is my innocent son back home with his two sisters and our grandchildren and have a big Christmas day.
"All the Christmases without Michael have obviously not been the same.
"It has been so hard for us all as a family.
"Even for his friends and campaigners, I can't explain the pain we've been through because it's been three-and-a-half years.
"I am just looking forward to Mr Straw getting Michael home as quickly as possible.
"I can't wait for the day we see him walking up the stairs into the house."
Speaking outside the family home which has become their campaign headquarters, Mr Shields pleaded with the Justice Secretary to free Michael as "everyone in the country knows Michael is innocent".
"Michael is 100% innocent and Mr Straw knows it," he said.
"He can exercise his power. We are the people who have voted this Government in and our Government should be looking after us and looking after innocent people.
"He shouldn't be in jail and I just hope Mr Straw can realise this is all wrong.
"How would he like it if his son was in prison for doing nothing?
"Michael was incarcerated for a crime he did not commit.
"It is very hard for us and Michael. We want Michael to be released as soon as possible, for our dream to come true with him coming home to his family.
"It is hard to stand here and give interviews because we simply shouldn't be doing this.
"We are a normal family and shouldn't be going through this heartache.
"Our Government should be standing up for its own."