That may be so. I am sure that the House would very much like to know how many blockade runners the Beira patrol has stopped while it has been on duty out there over the last six years or so, and what effect the patrol has had on the economy of Rhodesia, which it is supposed to be damaging. Obviously, any estimate of the effect on the economy of Rhodesia must be a guess, but it is one that we are entitled to know. I should also like to know how long Her Majesty's Government believe that we are to go on with this farce—because a farce it certainly is.

I should now like to turn to the security of the oil and other rigs in the North Sea, both now and in the future. I understand that at present there are 14 semi-submersible rigs in the northern North Sea with two jack-up types, making a total of 16. In the summer of next year there will be 50 and, as the hon. Member for West Lothian said, there will be 120 by 1980. In addition to that, there are already 26 completed platforms in the southern North Sea, so that is some measure of the problem that we have to face in this context. Furthermore, I understand that there are also nine or 10 permanent platforms in the course of construction. There is also quite a possibility that some of the oil, if not the gas, will be brought ashore by having totally submersed connecting points on the sea bed.

These are all potential targets for all sorts of weapons, not least wave-hopping aircraft. I understand that we have no proper airborne radar which is capable of dealing with that sort of problem, so the Navy and the Royal Air Force should be trying to get early warning radar aloft as quickly as possible. I submit that speedy action is essential. One possible answer to the problem of the wave-hopping aircraft is, alas, four years ahead—the versatile Type 22 frigate which will not be in service until later. It will have surface-to-surface as well as SAM missiles. I suggest that the half squadron of frigates which is needed for the wasteful Beira patrol could be withdrawn from that duty and trained specially for the protection of the rigs and platforms.

My hon. Friend the Member for Stretford (Mr. Churchill) rightly stressed the enormous preponderance of the USSR's ironmongery. I remind the House that the USSR will shortly have two aircraft carriers, whereas we are running down and will soon have none. The Russians already have 400 operational submarines, of which some 75 are nuclear powered, and they have a great many frigate-type vessels which are equipped with surface-to-surface missiles. I remind the House that by the 1980s the United Kingdom will be almost self-sufficient in oil. Can anybody doubt that the platforms and rigs would be a No. 1 priority for the Soviet marine forces if there were a general conflagration? A run-down in oil supplies in peacetime could cripple our economy. How much more would an attack on these rigs in wartime cripple our economy?

The hon. Member for West Lothian mentioned guerrilla attacks on these rigs and platforms. Anybody who wished to attack them, either now or in the future, must be made to think again. Not only could sabotage cause a great deal of trouble, disturbance and inconvenience, but any pollution would have a very serious effect upon our coastline and our very large fishing grounds in the North Sea. The other side of the coin is the damage that could be caused near the shore, or on the shore itself, by the fracturing of the landward or near-landward end of a pipeline. Therefore, the Ministry of Defence has a twofold yet unitary problem to face. First, we must fairly soon have highly mobile landward security forces to guard against or repulse attacks on the pipelines coming ashore, and there should be close co-operation with the oil industry to see that emergency repairs can be carried out quickly. Secondly, a very efficient communications network is necessary between the rigs and a shore-based naval and air headquarters. Such a headquarters should be established in the North-East of Scotland, independent of, but responsible to, the Flag Officer, Scotland.