THE treatment of jailed teenager Michael Shields could delay Bulgaria's entry to the European Union.
Foreign Secretary Jack Straw said that the European Commission has expressed reservations about the country's justice.
A fair legal system is a vital qualification for EU membership.
Riverside MP Louise Ellman has repeatedly claimed that the Liverpool fan's human rights were breached before and after his 15-year sentence for an attack on a local barman.
The Bulgarian courts refused to take into account new witness evidence and the signed confession of fellow Merseysider Graham Sankey.
Mr Straw told her: "Ultimately, the judgement on whether Bulgaria is fully ready for accession will take place at the end of this year or on January 1, 2007.
"It is a judgement that will have to be made by the European Union as a whole on the basis of recommendations by the commission.
"The commission has raised reservations about the quality of Bulgaria's justice system."
Whitehall insiders said that was the strongest hint so far that the UK will seek to delay membership until Michael, 19, receives justice.
Mr Straw added: "We are making, and will continue to make, strong representations to the government of Bulgaria.
"I have done so myself both to the Bulgarian foreign minister and to the prime minister, and I stand ready to do so again."
