Dr Julian Lewis: I shall directly address the point made by the Liberal Democrat spokesman, the hon. Member for Dunfermline and West Fife (Willie Rennie), about the long-term future. When he asks of the Conservative Party, "Will we always have nuclear weapons?", the answer is: "Yes, as long as other countries have nuclear weapons too". That is not a controversial viewpoint; that is the key point about unilateral nuclear disarmament that has resonated throughout the debate for the last half-century.

Twenty-five years ago, when I was working professionally in this sector and was arguing the case both for the replacement of Polaris by Trident and for the deployment of cruise missiles at Greenham Common and Molesworth, I commissioned a series of opinion polls that asked that very question: "Do you think that Britain should continue to possess nuclear weapons as long as other countries have them?" The answer that came in time and again throughout the 1980s, at the height of the second Cold War, was as follows: two thirds of people asked said, "Yes, we should continue to have the nuclear deterrent as long as other countries have nuclear weapons"; about one quarter said, "No"; and usually fewer than 10 per cent. of those asked – it was usually a single figure number – were undecided, because it is indeed a very polarising issue.

A couple of years ago, I asked the right hon. Member for Airdrie and Shotts (John Reid), the then Secretary of State for Defence, what polling evidence the Government had on such questions. The interesting written answer came back, on 3 November 2005, that the Government had last conducted a poll a few years earlier, in December 2003, and that

"Overall, some 66 per cent. agreed that the UK should retain nuclear weapons while other countries retain theirs, with 21 per cent. disagreeing". – [Official Report, 3 November 2005; Vol. 438, c. 1261W.]

So we can see a pattern continuing throughout the decades showing that about two thirds of the British people think that, as long as other countries have nuclear weapons, we should continue to possess them, and I believe that they are absolutely right to think that.

Jeremy Corbyn: I just want to tease out the hon. Gentleman's logic on this issue. Does he think that all countries everywhere in the world should have nuclear weapons to protect themselves from all the other people that may have nuclear weapons at some point in the future, and does he think that we should conduct an opinion poll to assess the popularity of arming the whole world with nuclear weapons?

Dr Lewis: I really thank the hon. Gentleman for entering into the spirit of the occasion. He and I have debated these points many times, so my response now will not come as anything of a surprise to him. I do not accept that there is an equality between stable democracies that have certain weapons systems, and lunatic dictatorships, which should not have them. I believe that there is no inconsistency in saying that it is perfectly acceptable for a democracy to be armed with a certain weapons system and a lunatic dictatorship to be denied it. I do not accept that there is an equality between dictatorships and democracies.

By way of example, I cite the attitude that we had towards Russia when it was a totalitarian Soviet state, and that we had when it ceased to be one. As soon as the dictatorial and aggressive element went out of the Russian political system – perhaps temporarily but hopefully permanently, despite recent adverse indications – we straight away stopped worrying about the Russian nuclear arsenal, except in one respect. Because we were no longer afraid that the Kremlin might use that arsenal aggressively, we began to worry instead that remnants or elements of that arsenal, including individual nuclear devices, would leech out and into the hands of other groups and regimes that would not hesitate to use such weapons aggressively if they could get their hands on them. So what matters is not the nature of the weapons themselves, but the nature of the regimes or groups that control them. It is perfectly acceptable for democracies to have these weapons while denying dictatorships the same right.

Stewart Hosie: I also want to tease out the hon. Gentleman's logic a bit further, because I presume that he will now go on to make the justification for Aldermaston and the nuclear weapons systems as a deterrent. However, if the democracy of the UK can have them but the mad dictator General Galtieri could not, can he explain why the deterrent factor did not work regarding the invasion of the Falklands?

Dr Lewis: I am absolutely delighted to explain that point to the hon. Gentleman in the following terms; indeed, if he would like to investigate them in more detail, they are fully covered in an essay that I distributed at the time of the debate on Trident last year. I am only sorry that he did not read it on that occasion; had he done so, he would not have had to ask me this question. The answer is that nuclear weapons deter a certain kind of threat – they deter countries from menacing us with weapons of mass destruction. They may deter some countries from menacing us in other ways, too, but they cannot be relied upon to do so. There was never the slightest possibility – and General Galtieri knew it – that we would use nuclear weapons in response to such a level of aggression as the invasion of the Falklands.

However, that is not to say that, just because nuclear weapons could not deter a conventional invasion of the Falklands, they serve no purpose. What the hon. Member for Dundee, East (Stewart Hosie) should ask himself is this. Supposing that we had had no nuclear weapons and that General Galtieri had had even a small number of them, would we then have dared to respond conventionally to his conventional invasion of the Falklands? The answer to that question is almost certainly not.

Let us return, however, to the main subject of the debate, which is Aldermaston. I wanted to start off by addressing the question put squarely by the Liberal Democrat spokesman, the hon. Member for Dunfermline and West Fife, and tell him what he wanted to discover about Conservative party policy. I think that I have done that in no uncertain terms.

Therefore, let me say belatedly, Mr [Martyn] Jones, what a pleasure it is to take part in this debate under your chairmanship. The last time that I served in Parliament under your chairmanship was on that memorable Welsh Affairs Select Committee from 1997 to 2001. You were a superb Chairman of that body, and I am sure that you will go on to establish an even more outstanding reputation as a Chairman on the Speaker's panel, as you evidently are intent on doing.

It is quite extraordinary that we should have embarked on the winding-up speeches in a debate on the future of nuclear weapons with something like 40 minutes still left to run, in a debate that was due to last one and a half hours. One could never have envisaged that happening in the past, and I must say that the hon. Member for Islington, North (Jeremy Corbyn) made a gallant attempt to explain this in advance – one might call it a sort of pre-emptive strike – by referring to the visit of President Sarkozy this afternoon. Dare I add that the visit of Madame Sarkozy this afternoon must be a huge draw away from Westminster Hall?

However, I think that the reality of the lack of interest in this debate on the part of the vast majority of Members lies somewhere else. It is that most people know that this argument is over. They know that the Labour party is not going to do what the right hon. Member for Manchester, Gorton (Sir Gerald Kaufman), one of its most prominent Back Benchers and a former shadow Foreign Secretary, said it would not do: it is not going to revisit the site of "the suicide". What he was referring to, as we all know, was

"the longest suicide note in history".

That is the manifesto of 1983, when the Labour party, under the leadership of Michael Foot, committed itself to getting rid of all our nuclear weapons while other countries continued to possess them. That commitment was a crucial factor in a landslide defeat for Labour in 1983, which was repeated in 1987.

The "suicide" to which the right hon. Member for Manchester, Gorton referred in the debate last year about nuclear weapons was the electoral suicide of the Labour party, and the Labour party is not going back there. The reason why it is not going back there is the figure that I quoted earlier, which has been so astonishingly consistent for so long in opinion poll after opinion poll, showing that two thirds of the British people think that it would be "suicide" to give up nuclear weapons while other countries continue to possess them.

Jeremy Corbyn: Since the hon. Gentleman is speaking for the Conservative Party, perhaps I can bring him round to what its views might be on the Non-Proliferation Treaty and the review conference coming up in 2010, because we are, after all, committed to long-term nuclear disarmament by our being a signatory to that treaty. All Governments have claimed adherence to that treaty.

Dr Lewis: The hon. Gentleman and I ought to consider going on the stage as a professional double act, because he seamlessly carries me forward in my argument. He has referred to Article VI of the Non-Proliferation Treaty, which I shall now read out, as I do in all debates on this issue. It states:

"Each of the Parties to the Treaty undertakes to pursue negotiations in good faith on effective measures relating to cessation of the nuclear arms race at an early date and to nuclear disarmament, and on a treaty on general and complete disarmament under strict and effective international control."

The last part about

"general and complete disarmament under strict and effective international control"

is always left out when CND supporters quote Article VI, as it means worldwide conventional disarmament. Article VI requires us to do three things, one of which is to end the nuclear arms race at an early date. Britain has never been involved in the nuclear arms race, and nor have France or China. Each of those three of the five recognised nuclear powers in the non-proliferation treaty regime has followed a policy of minimum strategic nuclear deterrence, which means that we are content to have a tiny proportion of nuclear devices, in comparison with the superpowers, because we know that having even that small number is enough for strategic nuclear deterrence purposes. Russia and the United States were involved in the nuclear arms race, not the UK.

Article VI also requires us to try to negotiate a treaty for worldwide nuclear disarmament and for worldwide conventional disarmament. Nothing in the article requires us to give up all our nuclear weapons before other countries do the same or before achieving a world Government to prevent an outbreak of conventional war on a grand scale – and by God, it was on a grand scale before nuclear weapons came along. Many more people were killed by conventional weapons in world wars one and two than died in Japan in August 1945. I venture to suggest, although I shall never be able to prove it, that many more would have been killed in "world war three" by conventional weapons or other countries’ nuclear weapons if the good people of Aldermaston, as well as the scientists, the people in the Royal Navy, and the people in the Royal Air Force before them, who constitute the strategic nuclear deterrent of the United Kingdom had not done their work so well. I appreciate the opportunity that the hon. Member for Islington, North has given me to pay tribute to the real peacekeepers of the Cold War and, I trust, the post-Cold War period – the men and women of Aldermaston and of the Royal Navy, and Royal Air Force before them.

I shall conclude soon, but first I shall address a few of the points that the hon. Gentleman made. He talked about the cost of Aldermaston. I refer him to a written answer that I received in December 2006 when I asked the Secretary of State for Defence

"what the running costs have been of the strategic nuclear deterrent in each of the past 10 years".

The answer was that they had ranged between

"3 and 5.5 per cent. of the annual defence budget." – [Official Report, 4 December 2006; Vol. 454, c. 87W.]

Of course, 3 per cent. or 5.5 per cent. of the annual defence budget is a large sum of money, but as a proportion of the defence budget, it is small. If there is a strategic justification for a weapons system, what more justification can one have than that it will deter others from using such a weapons system against one? Then, it is a small price to pay.

I commend my hon. Friend the Member for Newbury (Richard Benyon) on his excellent speech and the way in which he focused on the fundamental point about the unpredictability of conflict. He was absolutely right to pick on the conflicts that he mentioned: super-sensitive Israel was taken by surprise in 1973, and we were taken by surprise by the invasion of the Falklands in 1982. He was right to say that everyone was taken by surprise in 1990 when Saddam attacked Kuwait. He could also have mentioned that the world's only superpower was taken by surprise by 9/11 in 2001. I could cite examples from further back in history to show that when warfare breaks out, more often than not, it has not been predicted. It is a big mistake to assume that because weapons can do terrible things, the good guys should get rid of them regardless of what the bad guys do.

Finally, I shall address the Liberal Democrat contribution. Of course, CND says little about unilateralism these days, and tries to blur it in a general discussion about nuclear disarmament; it has always done that. I remember Bruce Kent arguing that he was both a unilateralist and a multilateralist, but one cannot be both. Either we keep nuclear weapons as long as other countries have them, or we say that we are going to get rid of them whether other countries have them or not. We cannot marry the two, and I know on which side of the argument my party and I stand on this life-and-death issue.