The BBC's Richard Hannaford on the Viagra debate

Pfizer says the government has had a year to decide what to do about the drug.

It submitted its application for a European licence a year ago.

Pfizer's UK chairman Ken Moran said: "I am amazed to find at the eleventh hour the day before Viagra is approved for use across Europe that doctors in the UK cannot prescribe it."

He added that the decision would create inequality, as men who could afford the drug would have access to it, while others would have to do without it.

Health Secretary Frank Dobson says that, although the drug has been licensed for use throughout Europe, doctors in the UK will not be allowed to prescribe it on the NHS until the government has made a considered decision about it.

No money

He told the BBC's Today programme that the price of the drug - at around £5 a pill - would have to come down.

Frank Dobson: "NHS's finances will be swamped"

He said: "Most people in this country don't think we should finance it through the health service as a sort of recreational drug at the expense of doing things which are more important."

Mr Dobson is worried that demand for the drug could drain NHS resources. One in 10 British men is reported to have an impotence problem.

However, he said Viagra should be available for some people who have had accidents or "suffer from certain physical conditions".

He also suggested the drug could be used in certain circumstances to treat infertility.

Depression

But impotence doctors say Mr Dobson is underestimating the impact of impotence on couples, both in health and emotional terms.

Frank Dobson: Cost concerns

Ken Moran said using Viagra could also cut other NHS costs, such as the price of treating impotent men for depression.

He added that, far from the government being concerned about the cost of the drug, Pfizer had received a letter from the Department of Health on Monday, confirming that the price of the drug, which has been recently reduced, was acceptable.

There are also suspicions that the move over the price of Viagra is linked to current talks between the government and the pharmaceutical industry over pricing of drugs.

UK doctors with private practices have been able to prescribe Viagra for some time on a named patient basis. This is where the doctor takes personal responsibility for what happens to the patient.

Mr Dobson said the government will seek "further expert guidance" and definitive advice on prescribing would be issued in the next few weeks.

Regret

The British Medical Association (BMA) has expressed regret at the announcement, although it does not want GPs to have to make a decision about who should and should not get Viagra.

Dr Ian Bogle: regrets postponement

Dr Ian Bogle, chairman of the association, said: "There has been an enormous amount of publicity about Viagra and this will have increased the expectations of patients with erectile dysfunction.

"Therefore I regret the postponement of a decision about the use of Viagra in the NHS."

He continued: "What is now required is a very clear decision from ministers based on evidence and professional advice as soon as possible."

Meanwhile, the Impotence Association says it has been flooded with calls from people who fear the government's ban on Viagra is final.