So-called alternative therapies could become far more easily available on the NHS, says the government.

It is considering moves to regulate the industry - and introduce medicines and treatments which prove themselves effective in clinical trials.

This, however, is unlikely to mean that many treatments get the go-ahead - so far, few have been shown to work in large scale tests.

Many GPs already prescribe so-called alternatives such as chiropractic, acupuncture and osteopathy to their patients, as there is some evidence in clinical trials suggesting a benefit.

There has been pressure from some groups to extend the use of herbal medicines and other non-mainstream treatments such as Ayurvedic medicine and homeopathy.

Weak evidence

However, the hard evidence supporting these treatments is far weaker, and well-conducted clinical trials which could support or dismiss them have been few and far between.

Last year, a House of Lords committee raised doubts about their value to patients.

The Department of Health said that moves were already underway for tougher regulations of the alternative therapy industry.

A spokesman said: "The National Institute for Clinical Excellence will be preparing guidelines on complementary therapy in palliative care.

"GPs can refer patients for complementary therapy on their clinical assessment of their patient's needs."

Herbal scares

There have been concerns that some herbal medicines - which contain potent chemicals - do not come under the same strict safeguards which govern the mainstream drug industry with regard to purity and safety.

In recent months, a particular Chinese herbal medicine was withdrawn, and warnings issued, after a group of patients suffered severe side-effects.

The British Medical Association welcomed the move, although they said that controls across the sector would have to be strict.

It has already called for access to acupuncture to be widened, following research suggesting it can help ease back and dental pain, migraine, nausea and vomiting.

A survey of GPs showed that 58% had arranged some kind of complementary or alternative therapy for their patients.

Many non-mainstream therapies have become far more popular in recent years - the Prime Minister's wife Cherie has been seen in public with an acupuncture needle in place on her ear.