I know exactly where I left off, Madam Speaker.

The disease was first identified in the 1860s by a French doctor. Until recently, it was regarded as untreatable, and no thought was given to how those suffering from it could be helped, advised and supported as its course progressed. I say "progressed", for, although the disease is at present incurable, many people are affected only marginally, if at all.

A quarter of those diagnosed as having MS are affected only mildly 15 years after the onset of the disease—they may have pins and needles in their fingers or toes—while a further quarter, tragically, end up in wheelchairs. The remaining 50 per cent. have the varied symptoms that characterise MS, which can include impaired co-ordination, problems with vision, loss of sensation and fatigue. One recently diagnosed constituent of mine told me that her arm sometimes felt as if it were full of molten metal. One in 15 people with MS will eventually become severely disabled.

MS typically affects more women than men, in the ratio 3:2, and strikes the young. That is what interested me in the condition in the first place. It hits people in the prime of life, often between the ages of 20 and 40. They have everything to look forward to; then comes the diagnosis that can change everything.

MS is common—it affects roughly one in every 1,000 people—but what causes it is still a mystery. No one knows why there are MS "clusters" in certain parts of the country, or why it increases according to latitude. It affects 99 people in every 100,000 in the south of England, but 178 per 100,000 in north-east Scotland. It used to be thought of as a disease that affected only Caucasians—and, curiously, non-white people who have settled here do not increase their chance of getting it, but their children acquire the risk faced by the general population. Many aspects of the disease are observed, but not understood.

Nevertheless, all is not gloom and despair. Things changed dramatically recently with the advent of new drugs that, it was claimed, would alter the course of the disease for those with relapsing-remitting MS, in which a person is free of the symptoms for a while but they often return with a vengeance. Peter Cardy, chief executive of the Multiple Sclerosis Society, wrote only a few months ago, in an article published in The House Magazine: For those who suffer severe relapses, the experience is like being dragged repeatedly to the jaws of death; blind, in pain and paralysed. Therefore, it is not surprising that the prospect of a drug that would deal with those dreadful symptoms has excited such interest.

Beta interferon helps people with remitting and relapsing MS—about 45 per cent. of the total number. The drug was given a product licence in December 1995, allowing it to be used not just in the UK, but throughout the European Union. In November 1995, the Department of Health issued guidelines on how it should be prescribed. I have read those guidelines cover to cover, and they put the frighteners on purchasers and on the consultant neurologist to whom would fall the clinical decision of whether beta interferon should be prescribed. The result of all that has been an enormous difference throughout the UK in the drug's availability.

The NHS guidance did not state categorically that all patients judged likely to benefit from the drug must receive it; the advice was much more circumspect. Providers—hospitals and so on—were asked to think about the resource implications of using beta interferon. It is expensive—£10,000 per patient per year—but we must set that against the annual cost to the economy of MS, which is about £1.2 billion in terms of lost taxes, increased benefits and so on.

Hospitals were told to consider workload and manpower implications for hospital neurologists and out patient departments. The guidance asks providers to consider the impact of providing the drug on waiting times, on consultant availability, on magnetic resonance imaging scans, on nursing and other support and, finally, on the hospital drugs budget. Couched in such a stern way, that advice clearly had an effect. In some parts of the UK, there was no access at all to beta interferon. On 10 December, I asked the Minister about the availability of beta interferon, and was told that that information was not collected centrally.

A survey was conducted by the manufacturer of the drug, Schering Pharmaceutical. It has a clear and obvious interest, but the figures it has provided to me are not necessarily tainted for that reason. The data relate to the period up to and including October 1996, almost a year after the initial guidance was issued, and just about the time that the latest and more positive advice went out from Dr. Winyard, medical director at the NHS executive.

The figures show the number of remitting-relapsing MS patients in each region and the percentage of purchasers—the health authorities—funding beta interferon in each region. In my Constituency in the north-west, all health authorities make provision for beta interferon, which is good. Of course, there is a second hurdle. The consultant neurologist has to decide whether to prescribe it, but the health authorities have made a decision whether to provide the money to purchase beta interferon, so someone in Manchester with relapsing or remitting MS would be all right, but someone in Edinburgh or in Dundee would not. In Scotland, only 35 per cent. of health authorities make provision; in Wales, only 5 per cent. do so; and in the English regions, only 5 per cent. do so in the northern and Yorkshire region.