I have already received two reactions in advance of my speech tonight on the possibilities of natural gas or hydrogen gas as a future fuel for vehicles.

The first reaction came from Mrs. Halliday, a lady whom I have never met and probably never shall. She telephoned me to say that, during world war two, methane-driven cars were used and that, in Wolverhampton, taxis ran on gas supplied by British Oxygen. I did not know that, and I am grateful to Mrs. Halliday for her helpful comments. I cannot say the same about the rather pathetic efforts of a local newspaper that managed the headline Chicken Dung Plan to Foil Saddam". I have read and respected that paper for many years, and it is a pity that it can treat such a serious subject in such a flippant manner.

The majority of my speech relates to research that has been conducted in the United States. It is more fearful of oil shortages than the United Kingdom, for understandable reasons. When the United States had its first oil shock a few years ago, many Americans started to think about alternatives to total dependence on fossil fuels. Two thirds of the oil consumed in the United States is burned by motor vehicles, but at present there are no practical substitutes for oil. American experts say that the most likely alternatives to gasoline or diesel will be methanol, compressed natural gas and electricity.

The essence of the problem is the general lack of knowledge on the subject. In Britain, when a problem goes away, we tend to forget about it until it recurs. The problem about oil has resurfaced now because of the Gulf conflict.

As environmental problems become more serious, and are taken more seriously, natural gas becomes a more important fuel than those of us who use it for our central heating and cooking have ever thought. Apart from the sun, wind and water power, natural gas is by far the cleanest source of energy. It could be the fuel of the future for motor vehicles, which are the greatest cause of pollution on our streets now.

A refrigerator can run on electricity, kerosene or gas. It may surprise people to learn that most bits of machinery, including motor cars, can be run on such energy sources. We are used to conventional cars that use regular or unleaded petrol, or diesel. Most of us are aware that various forms of gas, mostly methane and gases derived from sewage, have been used in the past to power vehicles. I accept that such ventures have been undertaken mostly out of curiosity or to promote a particular enterprise. For some years, Anglian Water has used escort vans powered by its home-produced gas. Such project have been experiments rather than serious operations.

Electric milk floats are common, but no one has ever produced a battery sufficiently compact, swift to charge and sufficiently powerful to take a full sized vehicle on the road for the normal distance required in the working day.

Why gas? At this time of the Gulf war, which is at least partly oil-related, there is every logic in looking for a basic fuel for vehicle propulsion that has its source in those countries that do not want to be dependent upon oil from the middle east.

In future, electricity generation will turn largely to gas in a co-generation role as opposed to the previously more conventional coal, or the long expected, but frankly distrusted, nuclear power.

In the past, everyone has assumed that gas, a finite substance, would run out at the end of this century or not far into the next century. For basically commercial reasons, gas stocks have always been underestimated. There is no doubt now that supplies in Europe alone are enough to keep us going well into the middle of the 21st century.

Gas is far less damaging to the environment than coal, or petroleum products. If I seem to swing between electricity generation and vehicle propulsion, that is simply because, for far too long, we have lived under a rather stratified form of science which assumes that energy for electricity generation comes from coal or nuclear and that energy for motor cars comes from petroleum products. When pressed, experts may accept that there are possibilities in gas or electric or even steam-driven vehicles, but these are considered unimportant, almost amusing, relics of past research.

The problem with new ideas is always that no one knows whether they will work in practice, even though they work in theory. So it was with gas vehicle propulsion. But no longer, although I was surprised to have to travel to Minnesota to find such propulsion not only acceptable but becoming almost mandatory at state level as a method of economic and environmentally sound propulsion.

In the USA, with its speed limit of 55 miles an hour, gas propulsion is acceptable, and I find it similar to diesel. Certainly gas-propelled vehicles have slower acceleration, but they have a good cruising speed and excellent fuel economy.

Ingenuity is the hallmark of the new gas engineer. In Minnesota, gas spigots are installed free of charge in people's garages if they possess a gas-powered car. They drive in at night, fill up overnight and drive off next morning without needing to fill up at a service station.

New service stations are now required to have facilities to fill up vehicles with gas as well as with diesel or petrol. That is all very sensible, but by and large none of these things have happened or even been accepted in this country as yet.

I chair the all-party alternative energy group, which is not against any form of power generation but which is much in favour of conservation—that famous fifth fuel—and the use of fuels which are efficient, economic and low in pollutants. Alas, I do not expect in my time to be able to offer the House a water-propelled car, but one day H₂0 may be split into hydrogen and oxygen and we shall get our gas fuel, if not from the tap, then at least from a local source.

I submit that gas propulsion is not only not eccentric but the logical future method of propulsion. It is economical to use, although I have no doubt that my right hon. Friend the Chancellor would soon slap the equivalent of a petrol tax on if it became a standard fuel. But my argument in favour of Government support, and Government consideration is also a request to the private commercial sector to consider whether it should not look at something unusual but not illogical. We have gone from theory to practice. For many years, we have been able to convert petrol-driven cars to gas, with a bulk cylinder filling the boot. Indeed, one of my hon. Friends has run a vehicle twice around the clock using gas. Yet I suspect that hon. Members did not know that or realise that the effect had been achieved.

For years, this conversion method has worked, and now the Americans are building cars with engines designed to run on gas. That is the logical way forward. General Motors has manufactured such a car, codenamed GMC 3500, I believe. Toronto Transit uses 40-seater buses that run entirely on natural gas.

Mrs. Sandra Hale, commissioner of administration in Minnesota, has said: The Mideast crisis has made energy conservation fashionable again but, in Minnesota state, good energy conservation never went out of fashion. When our Country's petroleum supplies were threatened in the 1970s, Governor Rudy Perpich initiated energy conservation measures that carried the State through the crisis. These measures became a permanent part of State operations because they made sense for the longer term. The results have been impressive. Energy-efficient compact vehicles predominate. Minnegasco is the local natural gas distributor in Minnesota. With its help, more than 20 commercial fleets have been converted to natural gas propulsion.

Also in the United States of America, the solar energy research institution in Golden, Colorado, is working on clean fuels such as the hythane system, whereby natural gas is blended with hydrogen towards an ultimate clean vehicle fuel. Nearer home, according to Automotive Engineering, May 1990, BMW is researching hydrogen-powered engines for some of its luxury cars. It will take a long time to make the full transition, but the beginning is there.

In the United Kingdom, British Gas recently acquired—with good timing, in view of my debate—Consumers Gas of Ontario, Canada's largest gas distribution company. British Gas is far from being some dreary old utility. It is now a huge international group seeking, treating and selling gas worldwide. Its chairman, Mr. Bob Evans, is a frequent visitor to the House, and confirms that the new company is fully committed to caring for the environment. He intends to spend $30 million in Canada on research and development, much of which will concentrate on the use of gas to power vehicles.

There are other good things to come. The Ricardo Group, a British research and development company, claims that natural gas is a high-quality engine fuel, and that existing petrol engines can be easily converted to use it. But that is the past. The group is now testing prototype gas bus engines on behalf of the co-Nordic natural gas project. This involves a consortium of five major Scandinavian urban bus companies, with the tightest emission controls anywhere in the world. There is already acceptance that the system works, and people are experimenting—but not shouting the news as loudly as I would like. British Gas, the leader, has been in the field for many years, and is now committed to research and development.