John Mills and Peter Hobbs from Enfield, north London, were hoping to fly home after being released halfway through a seven year sentence for smuggling drugs - a crime they have always denied.

The men have attacked the jail conditions in Sofia

But now they have been told their ordeal may last another fortnight until seats become available under a special deal between the Bulgarian authorities and a local airline.

The two were moved from prison in Sofia on Friday after successfully petitioning for early release.

Since then they have been held in a transit camp where conditions are understood to be even tougher than the jail, awaiting deportation.

Relatives of the two men, who have spent more than four years in jail, say they are "gutted" by the latest twist.

'Mental cruelty'

Peter Hobbs' sister-in-law Shirley said: "It's mental cruelty. We thought we'd be seeing them within days, now we don't know when it will be.

"We're desperate to get these men home but we just don't have the money to pay for flights.

"I can't believe what they're doing to these men."

Club class seats are available on a Balkan Bulgarian Airline flight on Friday, but the £250 price tag for each man is more than the Bulgarian government is prepared to pay.

It is insisting they wait for spaces under a special discount arrangement they have with the airline and will not pay for seats on another carrier.

A normal economy one-way fare would be around £160 but there is no availability until the end of next week.

The men could pay around £500 for seats on a British Airways flight on Thursday, but their families say that sort of money is out of their reach.

Lawyer Stephen Jakobi, of Fair Trials Abroad, has backed the men's claims that they were set up by drug gangs.

He said either the Bulgarians or the Foreign Office should be prepared to pay up to get them home.

He said: "This situation is extraordinary. I've never known anyone to be stuck in jail because of the expense of a flight."

'No resources'

A Foreign Office spokesman confirmed that the men were waiting for seats to become available under a special arrangement the Bulgarian government had with the airline.

He said the Foreign Office simply did not have the resources to pay for the repatriation of people in such circumstances and said they were being treated in accordance with local practice.

The two men were arrested in June 1995 after customs officials found 20kg of heroin hidden in an outside compartment of an empty lorry they were driving back to the UK.