A decision will be made this month on whether to grant jailed Liverpool fan Michael Shields an official pardon, Gordon Brown has indicated.
Justice Secretary Jack Straw can issue the pardon but has asked police to examine the Bulgarian conviction.
Mr Brown told the Commons Mr Straw would make the "best and fairest decision" he could.
Shields, 22, was transferred to the UK in 2006 after his 15-year sentence for attempted murder was reduced on appeal.
He was convicted of the attempted murder of a barman at the Black Sea resort of Varna in 2005 but has always maintained his innocence.
The High Court last year ruled that it was open to Mr Straw to entertain a request to exercise the royal prerogative to grant Shields a free pardon.
During Commons question time, Mr Brown said: "I understand the concerns about delay of the Shields family, they have waited a long time, he has got a large number of supporters.
"We are determined to make - that is the Justice Secretary who makes the decision - the best and fairest decision he can. But he can do so only after, in the public interest, assessing all the material that is available. And he expects to write to Mr Shields' lawyers later this month."
Confession retracted
Barman Martin Georgiev had a rock dropped on his head in May 2005.
Shields had been watching Liverpool's Champions League final win against AC Milan on television at the resort, along with other supporters.
He was found guilty of attempted murder in a trial in Bulgaria after the incident but has always maintained his innocence.
At one point another Liverpool fan, who was staying in the same hotel, signed a confession admitting he carried out the attack, but he later retracted it.
Shields, who was jailed in Bulgaria in July 2005, is currently serving his sentence at Thorn Cross Young Offenders' Institute in Warrington.
