Mr Shields' family wants the government to intervene

Liverpool Riverside MP Louise Ellman asked Mr Blair to meet Shields' family during Prime Ministers Questions.

More than 70,000 people have signed a petition urging the government to intervene in the 19-year-old's case.

Shields, of Wavertree, Liverpool, was jailed for 15 years by a Bulgarian court after being found guilty of the attempted murder of Martin Georgiev.

Another man, Graham Sankey, has said he attacked the barman but his confession was not accepted by the court.

I understand entirely the concerns of the Shields family Prime Minister Tony Blair

On Wednesday, Ms Ellman asked Mr Blair in the House of Commons: "Will you impress upon the Bulgarian authorities the seriousness of this situation and the determination of those supporting Michael Shields to seek justice?

"And will you agree to meet the Shields family at an appropriate time?"

Mr Blair said Foreign Secretary Jack Straw had raised the issue with the Prime Minister and Foreign Secretary of Bulgaria, but he refused to comment on the possibility of meeting the Shields family.

'Lost weight'

He said: "I understand entirely the concerns of the Shields family and the consular staff are doing all that they can to assist the Shields family and the legal team to prepare for the final appeal."

Ms Ellman and the Shields family handed in the petition at Downing Street on Wednesday.

Shields' mother, Maria, who visited her son last week, said: "He has lost an awful lot of weight. He is just a kid in a man's prison."

But she said he had made some friends inside.

Signed confession

Earlier in November, Shields failed in an attempt to get his jail sentence reduced.

He has consistently protested his innocence and maintains he was in bed when a paving slab was dropped on Mr Georgiev's head in the Black Sea resort of Varna.

Shields was there after watching Liverpool FC's Champions League victory in Turkey.