By Ray Furlong
BBC World at One reporter
The scheme is being pilotted at the West Middlesex
The government is looking for ways to stop 'health tourists' coming to Britain for free treatment to which they are not entitled.
A pilot project in London could be the future: money changes hands at the bedside and if you can't pay you are discharged within 48 hours.
On the stroke ward at the West Middlesex University Hospital, a middle-aged Indian man is facing just that prospect. Speaking Punjabi to a telephone translation service, he tells his story.
"I've been here four or five days," he says, his voice dazed and his arm quivering. "My friend pushed me and I fell down. I live here now."
But when Andy Finlay, Income Generation Manager at the hospital, takes the phone, he is not impressed.
"I have looked at his notes and he claimed to be an asylum seeker last year.
"What he is telling me now is a completely different story. I don't believe he's telling me the truth now, so I have made him liable for the cost of his treatment. Can you tell him that please?"
The hospital has a system called Stabilise and Discharge. Normally in the NHS, patients not eligible for free care receive a bill on departure from hospital - but only 30% of the money is recovered.
Here, patients pay up front or are discharged - usually within 48 hours.
"We will discharge a patient before they are well," says Andy Finlay.
"We will discharge a patient when they are stable, when we have provided what we have to provide - the minimum benchmark.
"Generally, within the first 48 hours after admission they will be given a price on how much, roughly, their treatment is going to cost.
"If I'm interviewing an inpatient I will be at that patient's bedside and I will ask them there and then for a visa, MasterCard, debit card, or cash. We don't take cheques."
A patient will only be discharged after three consultants have said their condition is stable.
Andy gives the example of a heart attack victim: usually they stay ten days in hospital - but they can be judged stable after 48 hours.
Most patients told to leave do so willingly - but not all of them.
"I've had two death threats, I've been held up against a wall, I've been grabbed round the throat, I've been manhandled by relatives - verbal abuse is almost day-to-day," says Andy.
"You have to have a very thick skin."
Figures on 'health tourism' are hard to come by, but a government report released under Freedom of Information rules last year, based on a sample of 12 NHS trusts, estimated £30m in un-recovered fees in 2004.
It identified maternity and HIV services as key problem areas. But there is resistance to charging.
"A year's HIV treatment is actually cheaper than three weeks in intensive care," says Lisa Power, from the Terrance Higgins Trust.
"The Department of Health has put out a notice to hospitals saying people should be given treatment but billed subsequently.
"But if you haven't got any money you exit treatment. Babies are being born with HIV as a direct result of their mothers being scared of charges."
Ms Power says there are differences within government over tightening the rules, because charges are also applied to various categories of people who live here both legally and illegally.
"From observation and from things that have been said to me it is clear that there are differing views from the Home Office and the Department of Health.
"The Home Office isn't too worried about bills on the NHS or the health of the nation. The Department of Health is.
"But there are also differences on this within the Department of Health."
Another government review is aimed at primary care: forcing GPs to charge non-eligible patients, something which is at present discretionary.
So far 89 MPs have signed an Early Day Motion against this, including 55 Labour members. GPs have also protested.
The evaluation of the system at West Middlesex University Hospital has been held up by delays to the primary care review.
But Andy Finlay says his methods have had an enthusiastic response from across Whitehall - and have saved the trust £600,000-£700,000 a year.
"They think it is a fantastic idea, a solution to a relatively new problem.
"It is up to the Department of Health to see how brave they will be to use innovative ways to tackle health tourism."
The Department of Health declined to make anyone available for interview to discuss the review and the pilot.
In a statement, it said: "It important that those who are not entitled to NHS services pay for†any they receive.†
"The government is currently reviewing access to primary and secondary care for all foreign nationals.
"In doing this we must take into account the implications of any such decisions on the key preventative and public health responsibilities of the NHS."