Packs of sterile maggots, which help patients to heal without long stays in hospital, have been barred from GPs' surgeries even though they have been awarded "Millennium Product" status by Tony Blair.
"Larval therapy" - the use of maggots on wounds - has been used for centuries and modern scientific tests have proved its efficacy.
Yet it is denied to thousands of injured patients and does not feature on the official list of approved medicines; only hospital consultants are allowed to buy the maggots. The Welsh laboratory that produces the packs is campaigning to put them on prescription and wants the Welsh Assembly to help.
The therapy, used widely in the First World War, has been credited in some cases with preventing amputation. The packs - the only supply of sterile maggots in the UK and the first in Europe - are produced by the NHS-run Surgical Materials Testing Laboratory at the Princess of Wales Hospital in Bridgend, Mid-Glamorgan.
Steve Thomas, the lab's director, said that the pounds 50 packs have been sold "by the back door" since they were developed three years ago. Purchasers are mainly consultants who have more freedom than other doctors and nurses to buy treatments not on the approved-drugs tariff.
Because the maggots are a live biological product they fall into a gap between the remits of the Medical Devices Agency and Medicines Control Agency.
Dr Thomas said: "The problem is that the drug tariff is only for pharmaceutical products or medical devices, which includes dressings. The legislation precludes sales of live origin. But the therapy could be much more widely used by community nurses in patients' own homes.
"We have got Millennium Product status. I think Tony Blair ought to know that government departments aren't talking to each other."
Dr Thomas is planning to raise the issue with the Welsh Assembly and Mr Blair at a reception for Millennium Product status holders in the New Year.
Because the maggots turn into flies after a few days, they are not suitable for exhibiting in the Millennium Dome, but will join an exhibition of all Millennium Products later.
Peter Vowden, a vascular surgeon at Bradford Royal Infirmary, has treated more than 300 patients with larval therapy. He says that in some cases it has avoided amputations and lengthy "debridement", where dead or infected tissue is removed.
"There are cases where larval therapy is undoubtedly the best method - heel ulcers close to the bone, for example," he said. "Hospital consultants have a great deal more freedom over the products they use. It doesn't need to be a recognised product on the drug tariff if you know enough about it."
Mr Vowden does not favour the packs being freely available to all clinicians, but to specialist wound-care nurses who are trained in using it. "Nurses have probably the greatest control over wounds and are the most appropriate people to use it. Doctors are not trained in wound care as part of the standard medical education, apart from those with a particular interest. A lot of them are vascular surgeons."
Maggots have been known for centuries to heal wounds, offering protection against gangrene and infection.
During the American Civil War, an army doctor wrote: "Maggots, in a single day, would clean a wound much better than any agents we had at our command. I am sure I saved many lives by their use." In the First World War, soldiers would deliberately put maggots in their wounds.
The advent of antibiotics in the 1940s saw the demise of the maggot as a therapeutic agent. The rise of resistant bacteria led to a resurgence of interest. Today, larval therapy is widely recognised as an efficient, cost-effective way of cleaning infected wounds and removing dead and infected tissue.