By Adam Brimelow
BBC News, health correspondent
Leading doctors say Afghanistan's opium-poppy harvest should be used to tackle an NHS shortage of diamorphine.
Doctors want Afghan poppy fields to be used for the NHS
The British Medical Association says using the poppy fields in this way, rather than destroying them, would help Afghans and NHS patients.
Diamorphine, also known as heroin, is used to relieve pain after operations and for the terminally ill.
But the UK and Afghan governments reject using the poppy fields to address the UK's diamorphine shortage.
However, UK doctors say the diamorphine shortage is getting worse, leaving them reliant on less effective, more expensive alternatives.
Dr Jonathan Fielden, a consultant in anaesthesia and intensive care medicine in Reading, said: "Unfortunately over the last year in particular, the availability of diamorphine has dramatically reduced.
"It's not clear why this is, but it has got to the stage where it is almost impossible in some hospitals to get hold of this drug for use outside very specific circumstances.
"This is a great shame because it is such a good drug".
The BMA has proposed a radical solution - harnessing the Afghan opium-poppy crop to produce diamorphine for the NHS.
It says this would benefit patients while providing much-needed income for Afghan farmers.
Dr Vivienne Nathanson, head of science and ethics at the BMA, said it was time for a new approach.
"If we actually were harvesting this drug from Afghanistan rather than destroying it, we'd be benefiting the population of Afghanistan as well as helping patients and not putting people at risk.
"There must be ways of harvesting it and making sure that the harvest safely reaches the drug industry which would then refine it into diamorphine.
"It should be possible, and really government and the international groups that are in Afghanistan should be looking at this and saying how can we convert it from being an illicit crop to a legal crop that is medicinally useful."
The Department of Health acknowledges there's been a shortage of diamorphine, but it says the situation is improving.
A spokeswoman said: "We have been in discussion with other possible entrants to the market, but there are barriers to be overcome.
"One of the problems is that diamorphine injection has to be freeze-dried.
"This is a specialised process and there is limited production capacity both in the UK and elsewhere in the world."
The Afghan authorities - backed by the UK government - reject the idea of local licensing to produce poppies for medicines.
They're stepping up their programme of poppy crop eradication, and prosecution of drug-traffickers.
However Emmanuel Reinert, executive director of the international think-tank The Senlis Council says destroying poppy crops will only encourage people to support the Taleban.
"The licensing system should be established at the village level, and the morphine should be produced at the village level.
"Therefore the mark-up will benefit directly to the villagers and the farmers and all the families.
"And it would be easy to export from the village to Kabul and then to the rest of the world, tablets from Afghanistan."
Other charities working in Afghanistan, including Christian Aid, are sceptical. They say the best solution is to provide long-term support such as irrigation projects to help farmers produce other crops.
Dr Fielden accepted that persuading the international community to try the idea would not be easy.
"The biggest difficulty will be changing the views of those countries, particularly the US, where this drug is banned.
"That will take a great cultural change to let them realise that a very cheap drug, easily produced, beneficial to patients, can be brought back in and used, rather than being seen as a drug of abuse."
Poppies contain morphine which has to be chemically modifed to produce diamorphine.